Pivotal bone anchor system with modular receiver sub-assemblies and universal bone anchors

ABSTRACT

A pivotal bone anchor system includes a plurality of bone anchors with rounded capture portions having a circumferentially extending outer engagement surface without flat side faces. The system also includes multi-planar receiver sub-assemblies, each comprising a multi-planar receiver defining a cavity with a multi-planar seating surface, and a multi-planar pivoting retainer configured for multi-planar motion upon engagement with both the multi-planar seating surface and the outer engagement surface of a bone anchor. The system further includes uni-planar receiver sub-assemblies, each comprising a uni-planar receiver defining a cavity with a uni-planar seating surface, and a uni-planar pivoting retainer configured for uni-planar motion upon engagement with the uni-planar seating surface and the outer engagement surface of another bone anchor. The capture portions of the bone anchors are configured for capture by either a multi-planar or uni-planar receiver sub-assembly without further modification or adjustment.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/275,923, filed Mar. 12, 2021, now U.S. Pat. No. 11,596,449, which isa U.S. National Phase Application under 35 U.S.C. § 371 of InternationalApplication No. PCT/US2019/051189, filed Sep. 13, 2019, which claims thebenefit of U.S. Provisional Application No. 62/731,023, filed Sep. 13,2018, and U.S. Provisional Application No. 62/810,361, filed Feb. 25,2019, each of which is incorporated by reference in its entirety herein,and for all purposes.

FIELD OF THE INVENTION

The present invention generally relates to pivotal bone anchorassemblies for use in bone surgery, particularly spinal surgery.

BACKGROUND

Bone screws are utilized in many types of spinal surgery in order tosecure various implants to vertebrae along the spinal column for thepurpose of stabilizing and/or adjusting spinal alignment. Although bothclosed-ended and open-ended bone screws are known, open-ended screws areparticularly well suited for connections to rods and connector arms,because such rods or arms do not need to be passed through a closedbore, but rather can be laid or urged into an open channel within areceiver or head of such a screw.

Typical open-ended bone screws include a threaded shank with a pair ofparallel projecting branches or arms which form a yoke defining slot orchannel having different shapes, such as U-shaped and square shaped, forexample, to receive a rod. Hooks and other types of connectors, as areused in spinal fixation techniques, may also include open ends forreceiving rods or portions of other structure.

A common mechanism for providing vertebral support is to implant bonescrews into certain bones which then in turn support a longitudinalstructure such as an elongate rod, or are supported by such a rod. Bonescrews of this type may have a fixed head or receiver relative to ashank thereof. In the fixed bone screws, the rod receiver head cannot bemoved relative to the shank and the rod must be favorably positioned inorder for it to be placed within the receiver head. This is sometimesvery difficult or impossible to do. Therefore, pivotal or polyaxial bonescrews are commonly preferred. Open-ended polyaxial bone screwstypically allow for pivoting and rotation of the separate receiver aboutthe shank in one or more planes until a desired rotational position ofthe receiver is achieved by fixing such position relative to the shankduring a final stage of a medical procedure when an elongate rod orother longitudinal connecting member is inserted into the receiver,followed by a locking set screw or other closure.

SUMMARY

Briefly described, one embodiment of the present disclosure comprises apivotal bone anchor system for securing an elongate rod to patient bone.The pivotal bone anchor system includes a plurality of bone anchors,with each bone anchor having a capture portion having a rounded shapeand an anchor portion extending downward from the capture portion forattachment to the bone. A horizontal capture recess extends into andcircumferentially around a midsection of each rounded capture portion.

The pivotal bone anchor system also includes one or more multi-planarreceiver sub-assemblies, with each multi-planar sub-assembly including amulti-planar receiver having a upper channel portion configured toreceive the elongate rod and a lower base portion defining an internalcavity with a substantially continuous circumferential partial sphericalmulti-planar seating surface proximate a bottom opening. Eachmulti-planar sub-assembly also includes a multi-planar retainer with apartial spherical outer surface configured for multi-planar motion uponengagement with the multi-planar seating surface, and an inner surfaceconfigured to snap into the bone anchor capture recess to capture thebone anchor within the multi-planar receiver cavity, and wherein thebone anchor is axially rotatable with respect to the retainer aftercapture.

The pivotal bone anchor system further includes one or more uni-planarreceiver sub-assemblies, with each uni-planar sub-assembly including auni-planar receiver having a upper channel portion configured to receivethe elongate rod and a lower base portion defining an internal cavitywith a non-continuous circumferential partial spherical uni-planarseating surface with opposing pockets proximate a bottom opening. Eachuni-planar sub-assembly also includes a uni-planar retainer with apartial spherical outer surface having opposing pegs projecting outwardtherefrom, and which is configured for uni-planar motion upon engagementwith the uni-planar seating surface and opposing pockets of theuni-planar receiver, and an inner surface configured to snap into thebone anchor capture recess to capture the bone anchor within theuni-planar receiver cavity, and wherein the bone anchor is axiallyrotatable with respect to the retainer after capture.

Furthermore, the capture portions of the plurality of bone anchors areconfigured for capture by either a multi-planar receiver sub-assembly ora uni-planar receiver sub-assembly without further modification oradjustment to the bone anchor capture portion.

The invention will be better understood upon review of the detaileddescription set forth below taken in conjunction with the accompanyingdrawing figures, which are briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a multi-planar pivotal boneanchor assembly, in accordance with a representative embodiment of thepresent disclosure.

FIG. 2 is an exploded perspective view of the bone anchor and a capturerecess protection sleeve of the multi-planar pivotal bone anchorassembly of FIG. 1 .

FIG. 3 is a cross-sectional perspective view of the shank head of thebone anchor of FIG. 2 .

FIG. 4 . is a cross-sectional view of the bone anchor of FIG. 2 .

FIG. 5 is a perspective view of the capture recess protection sleeve ofFIG. 2 .

FIG. 6 is a cross-sectional perspective view of the capture recessprotection sleeve of FIG. 2

FIG. 7 is a cross-sectional side view of the shank head and capturerecess protection sleeve of FIG. 2 prior to assembly.

FIG. 8 is a cross-sectional side view of the shank head and capturerecess protection sleeve of FIG. 2 after assembly.

FIG. 9 is a perspective view of the multi-planar receiver of themulti-planar pivotal bone anchor assembly of FIG. 1 .

FIG. 10 is a cross-sectional view of the multi-planar receiver of FIG. 9.

FIG. 11 is a cross-sectional perspective view of the multi-planarreceiver of FIG. 9 .

FIG. 12 is another cross-sectional perspective view of the multi-planarreceiver of FIG. 9 .

FIG. 13 is a perspective view of the pressure insert of the multi-planarpivotal bone anchor assembly of FIG. 1 .

FIG. 14 is a cross-sectional perspective view of the pressure insert ofFIG. 13 .

FIG. 15 is a cross-sectional side view of the pressure insert of FIG. 13.

FIG. 16 is a top view of the pressure insert of FIG. 13 .

FIG. 17 is a bottom view of the pressure insert of FIG. 13 .

FIG. 18 is an exploded perspective view of the multi-planar two-piecepositioner and positioner pins of the multi-planar pivotal bone anchorassembly of FIG. 1 .

FIG. 19 is a perspective view of a multi-planar positioner piece of FIG.18 .

FIG. 20 is a side view of a positioner pin of FIG. 18 .

FIG. 21 is a cross-sectional side view of a multi-planar positionerpiece of FIG. 18 assembled together with a positioner pin.

FIG. 22 is a perspective view of the multi-planar retainer of themulti-planar pivotal bone anchor assembly of FIG. 1 .

FIG. 23 is a cross-sectional perspective view of the multi-planarretainer of FIG. 22 .

FIG. 24 is a perspective view of the closure of the multi-planar pivotalbone anchor assembly of FIG. 1 .

FIG. 25 is a cross-sectional side view of the closure of FIG. 24 .

FIG. 26 is an exploded side view of the components of the multi-planarreceiver sub-assembly prior to their pre-assembly into a shippingconfiguration.

FIG. 27 is a partially cut-away side view of the multi-planar receiverof FIG. 26 with the multi-planar retainer being installed therein.

FIG. 28 is another partially cut-away side view of the multi-planarreceiver of FIG. 26 with the multi-planar retainer being installedtherein.

FIG. 29 is a partially cut-away side view of the multi-planar receiverof FIG. 26 with the multi-planar retainer installed therein.

FIG. 30 is a partially cut-away side view of the multi-planar receiverwith the installed multi-planar retainer and with a multi-planarpositioner piece being installed therein.

FIG. 31 is another partially cut-away side view of the multi-planarreceiver with the installed multi-planar retainer and with themulti-planar positioner piece being installed therein.

FIG. 32 is a partially cut-away side view of the multi-planar receiverwith the multi-planar retainer and both multi-planar positioner piecesinstalled therein.

FIG. 33 is a partially cut-away side view of the multi-planar receiverwith the multi-planar retainer, multi-planar positioner pieces, andpositioner pins installed therein.

FIG. 34 is a sectioned perspective view of the multi-planar receiver,multi-planar retainer, multi-planar positioner pieces, and positionerpins of FIG. 33 .

FIG. 35 is a partially cut-away side view of the multi-planar receiverwith the installed multi-planar retainer, multi-planar positionerpieces, and positioner pins, and with the pressure insert now beinginstalled therein.

FIG. 36 is a sectioned perspective view of the multi-planar receiver,multi-planar retainer, multi-planar positioner pieces, positioner pins,and pressure insert of FIG. 35 .

FIG. 37 is another partially cut-away side view of the multi-planarreceiver with the installed multi-planar retainer, multi-planarpositioner pieces, and positioner pins, and with the pressure insertbeing installed therein.

FIG. 38 is a sectioned perspective view of the multi-planar receiver,multi-planar retainer, multi-planar positioner pieces, positioner pins,and pressure insert of FIG. 37 .

FIG. 39 is another partially cut-away side view of the multi-planarreceiver with the installed multi-planar retainer, multi-planarpositioner pieces, and positioner pins, and with the pressure insertbeing rotated therein.

FIG. 40 is a sectioned perspective view of the multi-planar receiver,multi-planar retainer, multi-planar positioner pieces, positioner pins,and pressure insert of FIG. 39 .

FIG. 41 is another partially cut-away side view of the multi-planarreceiver with the installed multi-planar retainer, multi-planarpositioner pieces, and positioner pins, and with the pressure insertbeing fully installed therein.

FIG. 42 is a sectioned perspective view of the multi-planar receiver,multi-planar retainer, multi-planar positioner pieces, positioner pins,and pressure insert of FIG. 41 .

FIG. 43 is a partially cut-away side view of the multi-planar receivertogether with the installed and positioned multi-planar retainer,multi-planar positioner pieces, positioner pins, and pressure insertforming a pre-assembled multi-planar receiver sub-assembly.

FIG. 44 is a sectioned perspective view of the pre-assembledmulti-planar receiver sub-assembly of FIG. 43 .

FIG. 45 is a partially cut-away side view of the multi-planar receiversub-assembly positioned above the universal shank head of a bone anchorwith an attached capture recess protection sleeve.

FIG. 46 is a sectioned perspective view of the multi-planar receiversub-assembly and bone anchor of FIG. 45 .

FIG. 47 is a partially cut-away side view of the multi-planar receiversub-assembly moving downward to contact the universal shank head of thebone anchor and the top surface of the capture recess protection sleeve.

FIG. 48 is a sectioned perspective view of the multi-planar receiversub-assembly and bone anchor of FIG. 47 .

FIG. 49 is a partially cut-away side view of the multi-planar receiversub-assembly moving further downward until the constrained multi-planarretainer contacts the universal shank head and the capture recessprotection sleeve is pushed off the universal shank head.

FIG. 50 is a sectioned perspective view of the multi-planar receiversub-assembly and universal shank head of FIG. 49 .

FIG. 51 is a partially cut-away side view of the multi-planar receiversub-assembly moving further downward until the universal shank headcauses maximum expansion of the constrained multi-planar retainer.

FIG. 52 is a sectioned perspective view of the multi-planar receiversub-assembly and universal shank head of FIG. 51 .

FIG. 53 is a partially cut-away side view of the multi-planar receiversub-assembly moving further downward until the universal shank headreaches maximum push through within the receiver cavity.

FIG. 54 is a sectioned perspective view of the multi-planar receiversub-assembly and universal shank head of FIG. 53 .

FIG. 55 is a partially cut-away side view of the multi-planar receiversub-assembly moving back upward until the multi-planar retainer iscaptured within the horizontal capture recess of the universal shankhead.

FIG. 56 is a sectioned perspective view of the multi-planar receiversub-assembly and universal shank head of FIG. 55 .

FIG. 57 is a partially cut-away side view of the multi-planar receiversub-assembly moving further back upward until the multi-planar retainerbecomes seated on the receiver partial spherical seating surface.

FIG. 58 is a sectioned perspective view of the multi-planar receiversub-assembly and universal shank head of FIG. 57 .

FIG. 59 is a partially cut-away side view of the multi-planar receiversub-assembly and coupled universal shank head, with the pressure insertin a partially deployed position.

FIG. 60 is a sectioned perspective view of the multi-planar receiversub-assembly and universal shank head of FIG. 59 .

FIG. 61 is a partially cut-away side view of the multi-planar receiversub-assembly and coupled universal shank head, with the pressure insertin a fully deployed friction fit position.

FIG. 62 is a sectioned perspective view of the multi-planar receiversub-assembly and universal shank head of FIG. 61 .

FIG. 63 is a partially cut-way and sectioned perspective view of themulti-planar receiver sub-assembly and universal shank head of FIG. 61 .

FIG. 64 is another partially cut-way and sectioned perspective view ofthe multi-planar receiver sub-assembly and universal shank head of FIG.61 .

FIG. 65 is a partially cut-away and sectioned perspective view of themulti-planar receiver sub-assembly and coupled universal shank head in afriction fit position, with the bone anchor being pivoted relative tothe receiver.

FIG. 66 is another partially cut-away and sectioned perspective view ofthe multi-planar receiver sub-assembly and coupled universal shank headof FIG. 65 .

FIG. 67 is a partially cut-away and sectioned perspective view of themulti-planar receiver sub-assembly and coupled universal shank head, andfurther with an elongate rod and closure, in a partially lockedconfiguration with the bone anchor being pivoted relative to thereceiver.

FIG. 68 is another partially cut-away and sectioned perspective view ofthe multi-planar receiver sub-assembly, coupled universal shank head,elongate rod, and closure of FIG. 67 .

FIG. 69 is a partially cut-away and sectioned perspective view of themulti-planar receiver sub-assembly and coupled universal shank head withan elongate rod and closure in a fully locked configuration, therebyforming a completely assembled representative embodiment of amulti-planar pivotal bone anchor apparatus or system, with the boneanchor being pivoted relative to the receiver.

FIG. 70 is a cross-sectional side view of a universal shank head, inaccordance with another representative embodiment of the disclosure.

FIG. 71 is a cross-sectional side view of a retainer that is mateablewith the universal shank head of FIG. 70 .

FIG. 72 is a cross-sectional side view of the coupled universal shankhead and retainer of FIGS. 70 and 71 .

FIG. 73 is a cross-sectional side view of a universal shank head, inaccordance with yet another representative embodiment of the disclosure.

FIG. 74 is a cross-sectional side view of a retainer that is mateablewith the universal shank head of FIG. 73 .

FIG. 75 is a cross-sectional side view of the coupled universal shankhead and retainer of FIGS. 73 and 74 .

FIG. 76 is an exploded perspective view of a uni-planar pivotal boneanchor assembly, in accordance with another representative embodiment ofthe present disclosure.

FIG. 77 is a cross-sectional perspective view of the uni-planar receiverof the uni-planar pivotal bone anchor assembly of FIG. 76 .

FIG. 78 is another cross-sectional perspective view of the uni-planarreceiver of FIG. 77 .

FIG. 79 is a perspective view of the uni-planar retainer of theuni-planar pivotal bone anchor assembly of FIG. 76 .

FIG. 80 is a cross-sectional perspective view of the uni-planar retainerof FIG. 79 .

FIG. 81 is an exploded perspective view of the uni-planar two-piecepositioner and positioner pins of the uni-planar pivotal bone anchorassembly of FIG. 1 .

FIG. 82 is a perspective view of a uni-planar positioner piece of FIG.81 .

FIG. 83 is an exploded side view of the components of the uni-planarreceiver sub-assembly prior to their pre-assembly into a shippingconfiguration.

FIG. 84 is a partially cut-away side view of the uni-planar receiver ofFIG. 83 with the uni-planar retainer being installed therein.

FIG. 85 is another partially cut-away side view of the uni-planarreceiver of FIG. 83 with the uni-planar retainer being installedtherein.

FIG. 86 is a partially cut-away side view of the uni-planar receiver ofFIG. 83 with the uni-planar retainer installed therein.

FIG. 87 is a partially cut-away side view of the uni-planar receiverwith the installed uni-planar retainer and with a uni-planar positionerpiece being installed therein.

FIG. 88 is another partially cut-away side view of the uni-planarreceiver with the installed uni-planar retainer and with the uni-planarpositioner piece being installed therein.

FIG. 89 is a partially cut-away side view of the uni-planar receiverwith the uni-planar retainer and both uni-planar positioner piecesinstalled therein.

FIG. 90 is a partially cut-away side view of the uni-planar receiverwith the uni-planar retainer, uni-planar positioner pieces, andpositioner pins installed therein.

FIG. 91 is a sectioned perspective view of the uni-planar receiver,uni-planar retainer, uni-planar positioner pieces, and positioner pinsof FIG. 90 .

FIG. 92 is a partially cut-away side view of the uni-planar receiverwith the installed uni-planar retainer, uni-planar positioner pieces,and positioner pins, and with the pressure insert now being installedtherein.

FIG. 93 is a sectioned perspective view of the uni-planar receiver,uni-planar retainer, uni-planar positioner pieces, positioner pins, andpressure insert of FIG. 92 .

FIG. 94 is another partially cut-away side view of the uni-planarreceiver with the installed uni-planar retainer, uni-planar positionerpieces, and positioner pins, and with the pressure insert now beinginstalled therein.

FIG. 95 is a sectioned perspective view of the uni-planar receiver,uni-planar retainer, uni-planar positioner pieces, positioner pins, andpressure insert of FIG. 94 .

FIG. 96 is another partially cut-away side view of the uni-planarreceiver with the installed uni-planar retainer, uni-planar positionerpieces, and positioner pins, and with the pressure insert being rotatedtherein.

FIG. 97 is a sectioned perspective view of the uni-planar receiver,uni-planar retainer, uni-planar positioner pieces, positioner pins, andpressure insert of FIG. 96 .

FIG. 98 is another partially cut-away side view of the uni-planarreceiver with the installed uni-planar retainer, uni-planar positionerpieces, and positioner pins, and with the pressure insert being fullyinstalled therein.

FIG. 99 is a sectioned perspective view of the uni-planar receiver,uni-planar retainer, uni-planar positioner pieces, positioner pins, andpressure insert of FIG. 98 .

FIG. 100 is a partially cut-away side view of the uni-planar receivertogether with the installed and positioned uni-planar retainer,uni-planar positioner pieces, positioner pins, and pressure insertforming a pre-assembled uni-planar receiver sub-assembly.

FIG. 101 is a sectioned perspective view of the pre-assembled uni-planarreceiver sub-assembly of FIG. 100 .

FIG. 102 is a partially cut-away side view of the uni-planar receiversub-assembly positioned above the universal shank head of a bone anchor.

FIG. 103 is a sectioned perspective view of the uni-planar receiversub-assembly and bone anchor of FIG. 102 .

FIG. 104 is a partially cut-away side view of the uni-planar receiversub-assembly moving downward to contact the universal shank head of thebone anchor.

FIG. 105 is a sectioned perspective view of the uni-planar receiversub-assembly and bone anchor of FIG. 104 .

FIG. 106 is a partially cut-away side view of the uni-planar receiversub-assembly moving further downward until the constrained uni-planarretainer contacts the universal shank head.

FIG. 107 is a sectioned perspective view of the uni-planar receiversub-assembly and universal shank head of FIG. 106 .

FIG. 108 is a partially cut-away side view of the uni-planar receiversub-assembly moving further downward until the universal shank headcauses maximum expansion of the constrained uni-planar retainer.

FIG. 109 is a sectioned perspective view of the uni-planar receiversub-assembly and universal shank head of FIG. 108 .

FIG. 110 is a partially cut-away side view of the uni-planar receiversub-assembly moving further downward until the universal shank headreaches maximum push through within the receiver cavity.

FIG. 111 is a sectioned perspective view of the uni-planar receiversub-assembly and universal shank head of FIG. 110 .

FIG. 112 is a partially cut-away side view of the uni-planar receiversub-assembly moving back upward until the uni-planar retainer iscaptured within the horizontal capture recess.

FIG. 113 is a sectioned perspective view of the uni-planar receiversub-assembly and universal shank head of FIG. 112 .

FIG. 114 is a partially cut-away side view of the uni-planar receiversub-assembly moving further back upward until the uni-planar retainerbecomes seated on the receiver partial spherical seating surface.

FIG. 115 is a sectioned perspective view of the uni-planar receiversub-assembly and universal shank head of FIG. 114 .

FIG. 116 is a partially cut-away side view of the uni-planar receiversub-assembly and coupled universal shank head, with the pressure insertin a fully deployed friction fit position.

FIG. 117 is a sectioned perspective view of the uni-planar receiversub-assembly and universal shank head of FIG. 116 .

FIG. 118 is a partially cut-way and sectioned perspective view of theuni-planar receiver sub-assembly and universal shank head of FIG. 116 .

FIG. 119 is another partially cut-way and sectioned perspective view ofthe uni-planar receiver sub-assembly and universal shank head of FIG.116 .

FIG. 120 is a partially cut-away and sectioned perspective view of theuni-planar receiver sub-assembly and coupled universal shank head in afriction fit position, with the bone anchor being pivoted relative tothe receiver.

FIG. 121 is another partially cut-away and sectioned perspective view ofthe uni-planar receiver sub-assembly and coupled universal shank head ofFIG. 120 .

FIG. 122 is a partially cut-away and sectioned perspective view of theuni-planar receiver sub-assembly and coupled universal shank head, andfurther with an elongate rod and closure, in a partially lockedconfiguration with the bone anchor being pivoted relative to thereceiver.

FIG. 123 is another partially cut-away and sectioned perspective view ofthe uni-planar receiver sub-assembly, coupled universal shank head,elongate rod, and closure of FIG. 122 .

FIG. 124 is a partially cut-away and sectioned perspective view of theuni-planar receiver sub-assembly and coupled universal shank head withan elongate rod and closure in a fully locked configuration, therebyforming a completely assembled representative embodiment of a uni-planarpivotal bone anchor apparatus or system, with the bone anchor beingpivoted relative to the receiver.

FIG. 125 is a perspective view of a pair of multi-planar pivotal boneanchor assemblies, each with housings configured for adjacent levelconnection, in accordance with another representative embodiment of thepresent disclosure.

FIG. 126 is another perspective view of the pair of multi-planar pivotalbone anchor assemblies of FIG. 125 .

FIG. 127 is a perspective view of one of the multi-planar pivotal boneanchor assemblies of FIG. 125 .

FIG. 128 is a partially cut-away perspective view of the multi-planarpivotal bone anchor assembly of FIG. 127 .

FIG. 129 is another partially cut-away perspective view of themulti-planar pivotal bone anchor assembly of FIG. 127 .

FIG. 130 is another partially cut-away perspective view of themulti-planar pivotal bone anchor assembly of FIG. 127 .

FIG. 131 is a perspective view of a multi-planar pivotal bone anchorassembly with a housing configured for adjacent level connection, inaccordance with another representative embodiment of the presentdisclosure.

FIG. 132 is a partially cut-away perspective view of the multi-planarpivotal bone anchor assembly of FIG. 131 .

FIG. 133 is a perspective view of a pair of multi-planar pivotal boneanchor assemblies with housings configured for adjacent levelconnection, in accordance with yet another representative embodiment ofthe present disclosure.

FIG. 134 is a partially cut-away perspective view of the pair ofmulti-planar pivotal bone anchor assemblies of FIG. 133 .

Those skilled in the art will appreciate and understand that, accordingto common practice, various features and elements of the drawingsdescribed above are not necessarily drawn to scale, and that thedimensions and relative positions between the features or elements maybe expanded, reduced or otherwise altered to more clearly illustrate thevarious embodiments of the present disclosure depicted therein.

DETAILED DESCRIPTION

The following description, in conjunction with the accompanying drawingsdescribed above, is provided as an enabling teaching of exemplaryembodiments of a pivotal bone anchor apparatus, assembly, or system thatgenerally includes a universal shank head for use with a plurality ofdifferent types of functional modular receiver sub-assemblies, togetherwith methods for assembling and using the pivotal bone anchor apparatus,assembly, or system. As described below, the apparatuses, assemblies,systems, and/or methods of the present disclosure can provide severalsignificant advantages and benefits over other pivotal bone anchorsknown in the art. However, the recited advantages are not meant to belimiting in any way, as one skilled in the art will appreciate thatother advantages may also be realized upon practicing the presentdisclosure.

Furthermore, those skilled in the relevant art will recognize thatchanges can be made to the described embodiments while still obtainingthe beneficial results. It will also be apparent that some of theadvantages and benefits of the described embodiments can be obtained byselecting some of the features of the embodiments without utilizingother features, and that features from one embodiment may beinterchanged or combined with features from other embodiments in anyappropriate combination. For example, any individual or collectivefeatures of method embodiments may be applied to apparatus, product orsystem embodiments, and vice versa. Accordingly, those who work in theart will recognize that many modifications and adaptations to theembodiments described are possible and may even be desirable in certaincircumstances, and are a part of the disclosure. Thus, the presentdisclosure is provided as an illustration of the principles of theembodiments and not in limitation thereof, since the scope of theinvention is to be defined by the claims.

Referring now in more detail to the drawing figures, wherein like partsare identified with like reference numerals throughout the severalviews, FIG. 1 illustrates a representative embodiment of a multi-planarpivotal bone anchor apparatus or assembly 10 (hereinafter referenced toas “the multi-planar assembly 10”) for securing an elongate rod topatient bone in spinal surgery. The multi-planar assembly 10 generallyincludes a bone anchor, such as shank 20, having a capture portion, suchas universal shank head 22, at a proximal end 23, and an anchor portionor shank body 40 extending distally from the shank head 22 forsecurement to patient bone. The multi-planar assembly also generallyincludes a multi-planar receiver 100 having an internal cavity 126 in abase portion 134 and two upright arms 104 extending upwardly from thebase portion to define a rod channel 106 for receiving an elongate rod90. The multi-planar receiver 100 can be initially pivotably secured tothe universal shank head 22 with a number of separate internalcomponents that have been pre-assembled into the internal cavity 126 andthe rod channel 106 to form a receiver sub-assembly. These componentscan include a multi-planar resilient open pivoting retainer 70, apressure insert 150, and a single piece or multi-piece positioner 170that may secured in different ways within the internal cavity 126 of thebase portion 134, for example, with positioner pins 190. After anelongate rod 90 has been positioned within a lower portion of the rodchannel 106, a closure 80 can be threadably or otherwise secured into anupper portion of the rod channel to apply pressure to an upper surfaceof the elongate rod, thereby locking both the elongate rod 90 and themulti-planar assembly 10 into a final locked position.

Also shown in FIG. 1 , in one aspect of the disclosure the bone anchoror shank 20 can further include an optional removable resilient capturerecess protection sleeve 50 installed over a horizontal capture recess32 that is formed into the universal shank head 22 or capture portion ofthe bone anchor, so as to prevent soft tissue and bone chips fromentering and fouling the capture recess 32 prior to introduction of theuniversal shank head 22 into a receiver sub-assembly, as described inmore detail below.

With reference to FIGS. 2-8 , the bone anchor or shank 20 generallycomprises a capture portion or shank head 22 at a proximal end 23 havinga universal shank head structure, and an anchor portion or shank body 40extending distally from the universal shank head 22 toward a tip 48 at adistal end 49. The shank 20 is elongate, with the shank body 40 having ahelically wound bone implantable thread 44 (single, dual, ormultiple-lead thread form) extending from near a neck 42 locatedadjacent to the shank head 22, to a distal tip 48 of the body 40 andextending radially outwardly therefrom. During use, the shank body 40utilizing the thread 44 for gripping and advancement is implanted intothe vertebra (not shown) of a patient leading with the tip 48 and drivendown into the vertebra with an installation or driving tool (also notshown), so as to be implanted in the vertebra to near the neck 42 of theshank 20, as more fully described in the paragraphs below. The shank 20has a central longitudinal axis, or axis of rotation, that is generallyidentified by the reference numeral 21.

The neck 42 extends axially upward from the shank body 40. The neck 42may be of the same or is typically of a slightly reduced radius ascompared to an adjacent upper end of the shank body 40 where the thread44 terminates. In one aspect the threaded shank body 40 and the neck 42can together define an anchor portion of the shank 20. Further extendingaxially and outwardly from the neck 42 is the universal shank head 22that provides a connective or capture apparatus disposed at a distancefrom the shank body 40, and thus at a distance from the vertebra whenthe shank body 40 is implanted in such vertebra.

The universal shank head 22 is configured for a pivotable connectionbetween the shank 20 (with attached retainer 70) and the multi-planarreceiver 100 prior to fixing of the shank 20 in a desired position withrespect to the multi-planar receiver 100. The universal shank head 22has an outer, convex and partial spherical lower surface 38 that extendsoutwardly and upwardly from the neck 42 and terminates at lowercylindrical surface 36 that can be substantially parallel to the shankaxis 21, and having a radius smaller than the radius of the sphericallower surface 38. The partial spherical lower surface 38 has an outerradius that is the same or substantially similar to an outer radius ofthe multi-planar retainer 70, as will be described in greater detailbelow, with the partial spherical surface 38 and the partial sphericalouter surface of the multi-planar retainer 70 participating in the balland socket joint formed by the shank 20 and the attached multi-planarretainer 70 within a partial spherical seating surface 132 defining alower portion of the cavity 126 of the multi-planar receiver 100. (seeFIGS. 10-12 ).

The lower cylindrical surface 36 extends upward to a lower annular shelfor ledge surface 35 that is disposed perpendicular to the shank axis 21.Extending upwardly from the lower ledge surface 35 is anoutwardly-facing inner recess surface 34 having a radius that is smallerthan the radius of the lower cylindrical surface 36. Extending outwardlyfrom the inner recess surface 34 is another annular self or upper ledgesurface 33 that faces toward the lower ledge surface 35 and is alsosubstantially perpendicular to the shank longitudinal axis 21. As willbe discussed in greater detail below, the upper ledge surface 33, theinner recess surface 34, and the lower ledge surface 35 together definea circumferential horizontal capture recess 32, and cooperate to captureand fix the resilient open pivoting multi-planar retainer 70 to theuniversal shank head 22, prohibiting movement of the multi-planarretainer 70 in the direction of the shank axis 21 once the multi-planarretainer 70 is located between the ledges 33 and 35.

As will be described in greater detail below, the structure of theuniversal shank head 22 having the circumferential horizontal capturerecess 32, as shown in FIGS. 2-4 , allows for the shank head 22 toconnect with either a multi-planar or a uni-planar receiversub-assembly, and in particular with either a multi-planar or auni-planar pivoting retainer which is engageable with a complementarymulti-planar or uni-planar receiver, respectively. This feature of thepivotal bone anchor assembly or system can advantageously provide forselectable multi-planar or uni-planar motion of a receiver with respectto the shank head 22, as determined by a surgeon or medical professionalin an operating environment after implantation of the shank body 44 intoa vertebra, but prior to the coupling or capture of the shank head 22with a respective receiver sub-assembly. As defined herein, thecapability of connecting with either a multi-planar or a uni-planarreceiver sub-assembly in an operating environment, to the same shankhead geometry without further configuration or modification thereto, isuseful for designating the shank head 22 as a universal shank head.

Furthermore, it will be appreciated that the horizontal capture recess32 extends circumferentially entirely around the universal shank head22, without any planar surfaces or flats being formed into the sides ofthe shank head 22. This results in a continuous 360 degree contactbetween the universal shank head 22, the multi-planar retainer 70, andthe receiver seating surface 132 (FIGS. 10-12 ) that avoids high-stressdiscontinuities while providing for a smooth continuous engagementbetween the internal components that resists pull-out at all angulationangles. In a multi-planar embodiment, such as that shown in FIGS. 1-69 ,the partial spherical outer surface 74 of the resilient open pivotingretainer 70 and the partial spherical seating surface 132 of thereceiver cavity 126 are substantially continuous (except for theretainer slot) and unbroken, providing for polyaxial, multi-axial, ormulti-planar pivotal motion between the shank 20 and the multi-planarreceiver 100. In a uni-planar embodiment, such as that shown in FIG.76-124 , the partial spherical outer surface of the resilient openretainer and the partial spherical seating surface of the receivercavity are modified to include outwardly-projecting pegs andinwardly-extending pockets, respectively, that restrict the pivotalmotion between the shank and the receiver to a single plane.Nevertheless, the continuous 360 degree contact between the shank head,the retainer, and the receiver seating surfaces is still maintained inthe uni-planar embodiment to provide a secure pull-out resistantconnection between the components at all angulation angles, again, whileall using the same shank head geometry.

As shown in the bone anchor embodiment of FIGS. 2-8 , in one aspect theinner recess surface 34 can have a curved profile that gradually curvesdownwardly and outwardly as moving from the upper ledge surface 33 tothe lower ledge surface 35, and which can be complementary with acurvate inner surface 76 of the resilient open multi-planar retainer 70(see FIGS. 22-23 ). Nevertheless, it is understood that the inner recesssurface 34 can have a variety of profiles, including but not limited toa cylindrical profile, a frusto-conical profile, a reversed curvedprofile that gradually curves downwardly and inwardly as moving from theupper ledge surface 33 to the lower ledge surface 35, and the like. Inaddition, the profile of the inner recess surface 34 may or may not beclosely complementary with and engaged by the inner surface of theresilient open pivoting multi-planar retainer 70.

Extending upwardly from the upper ledge surface 33 is an uppercylindrical surface 30 having a radius that is substantially equal tothe radius of the lower cylindrical surface 36. Extending furtherupwardly from the upper cylindrical surface 30 is an upper partialspherical or domed surface 28. The upper partial spherical surface 28has an outer radius configured for sliding cooperation and ultimatefrictional mating with a substantially spherical concave bottom surface166 of the pressure insert 150 (see FIGS. 14-15 ) that has the same orsubstantially similar radius as the partial spherical surface 28. Inaddition, the radius of the upper partial spherical surface 28 cansubstantially equal to both the radius of the lower partial sphericalsurface 38 and the partial spherical outer surface 74 of themulti-planar retainer 70 (see FIGS. 22-23 ), so that the three partialspherical surfaces 28, 74, 38 align, when the resilient openmulti-planar retainer 70 is captured or secured within the capturerecess 32, to form a united universal shank head 22/multi-planarpivoting retainer 70 structure that is substantially spherical.

Located near or adjacent to the upper partial spherical surface 28 is anannular planar top surface 26 that surrounds an internal drive feature24 or drive socket. The illustrated internal drive feature 24 is anaperture formed in the top surface 26 and has a hex shape designed toreceive a hex tool (not shown) of an Allen wrench type, into theaperture for rotating and driving the shank body 40. It is foreseen thatsuch an internal tool engagement structure may take a variety oftool-engaging forms and may include one or more apertures of variousshapes, such as a pair of spaced apart apertures or a multi-lobular orstar-shaped aperture, such as those sold under the trademark TORX, orthe like. The seat or base surface 25 of the drive feature 24 isdisposed perpendicular to the shank axis 21, with the drive feature 24otherwise being coaxial with the axis 21. In operation, a driving toolis received in the internal drive feature 24, being seated at the basesurface 25 and engaging the six faces of the drive feature 24 for bothdriving and rotating the shank body 40 into the vertebra, either beforeor after the shank 20 is attached to the receiver sub-assembly 146, withthe shank body 40 being driven into the vertebra with the driving toolextending into the multi-planar receiver 100.

In one aspect the shank 20 can be cannulated, with a bore 46 extendingthrough the entire length thereof, and centered about the centrallongitudinal axis 21 of the shank 20. The bore 46 is defined by an innercylindrical wall of the shank 20 and has a circular opening at the shanktip 48 and an upper opening communicating with the internal drive 24 atthe surface 25. The bore 46 is coaxial with the threaded shank body 40and the universal shank head 22. The bore 46 provides a passage throughthe shank 20 interior for a length of wire (not shown) inserted into thevertebra prior to the insertion of the shank body 40, the wire providinga guide for insertion of the shank body 40 into the vertebra. The borecan also provide for a pin to extend therethrough and beyond the shanktip, the pin being associated with a tool to facilitate insertion of theshank body into the vertebra.

To provide a biologically active interface with the bone, the threadedshank body 40 may be coated, perforated, made porous or otherwisetreated. The treatment may include, but is not limited to a plasma spraycoating or other type of coating of a metal or, for example, a calciumphosphate; or a roughening, perforation or indentation in the shanksurface, such as by sputtering, sand blasting or acid etching, thatallows for bony ingrowth or ongrowth. Certain metal coatings act as ascaffold for bone ingrowth. Bio-ceramic calcium phosphate coatingsinclude, but are not limited to: alpha-tri-calcium phosphate andbeta-tri-calcium phosphate (Ca₃(PO₄)₂, tetra-calcium phosphate(Ca₄P₂O₉), amorphous calcium phosphate and hydroxyapatite(Ca₁₀(PO₉)₆(OH)₂). Coating with hydroxyapatite, for example, isdesirable as hydroxyapatite is chemically similar to bone with respectto mineral content and has been identified as being bioactive and thusnot only supportive of bone ingrowth, but actively taking part in bonebonding.

With particular reference to FIGS. 5-8 , the optional removable capturerecess protection device or sleeve 50 generally comprises a resilient orflexible sleeve body 54 that is sized and shaped to fit firmly over thecapture recess 32 during installation of the bone anchor into patientbone prior to the shank 20 being attached to the receiver sub-assembly146, as shown in FIGS. 45-64 . The sleeve body 54 generally has a topsurface 53, a bottom surface 55, an outer surface 56, and in innersurface 58 with a inwardly protruding raised cylindrical structure 62defined by an upper edge 61 and a lower edge 63. An upper innercylindrical surface 60 extends between upper edge 61 and the top surface53 of the sleeve body, with a mirroring lower inner cylindrical surface64 extending between lower edge 63 and the bottom surface 55 of thesleeve body. In one aspect the upper and lower edge surfaces 61, 63 ofthe raised cylindrical structure 62 can taper toward a center of theraised cylindrical structure 62 as projecting inwardly from the innercylindrical surfaces 60, 64. It will be appreciated that the disclosedembodiment of the capture recess protection sleeve 50 is only exemplary,and that other embodiments and configurations for the protection sleeveare also possible and considered to fall within the scope of the presentdisclosure, particularly with having the functionality of preventingmaterial from entering the shank capture recess.

Upon installation of the capture recess protection sleeve 50 to theuniversal shank head 22, as illustrated in FIG. 8 , the upper and loweredge surfaces 61, 63 are generally sized to fit between the upper andlower ledge surfaces 33, 35 of the capture recess 32, so that the raisedcylindrical structure 62 projects cleanly into the capture recess 32.This can allow for the upper and lower inner cylindrical surfaces 60, 64of the sleeve 50 to resiliently engage the upper and lower cylindricalsurfaces 30, 36 of the shank head 22, respectively, to provide a firmbut flexible seal that prevents soft tissue and bone chips from enteringand fouling the capture recess 32 prior to the installation of thepre-assembled receiver sub-assembly.

The capture recess protection sleeve 50 can be made from a flexible,resilient, or semi-resilient material, such as a polymer or soft metal,and some embodiments can be made from a bio-degradable polymer orsimilar material. In one embodiment the capture recess protection sleeve50 can include a lanyard (not shown) that allows the surgeon to manuallypull the sleeve 50 off of the shank head during attachment of thereceiver sub-assembly. In another embodiment the sleeve 50 may also beprovided with a pre-formed shear or tear line (not shown) opposite thelanyard attachment point that allows for the sleeve 50 to be split ortorn apart after being pushed down into the neck area of the bone anchoror shank 20, facilitating removal of the sleeve by the lanyard afteruse.

Illustrated in FIGS. 9-12 is the multi-planar receiver having agenerally U-shaped appearance with a partially discontinuoussubstantially cylindrical inner profile and a partially cylindrical andpartially faceted outer profile, although other profiles arecontemplated. The multi-planar receiver 100 also has a centrallongitudinal axis 101, or axis of rotation, that is shown in FIG. 1 asbeing aligned with the central longitudinal axis 21 of the shank 20,such orientation being desirable, but not required during assembly ofthe multi-planar receiver 100 with the shank 20. After the receiver 100is pivotally attached to the universal shank head 22, either before orafter the shank 20 is implanted in a vertebra, the receiver axis 101 istypically disposed at an angle with respect to the shank axis 21 asshown, for example, in FIGS. 65-69 .

The multi-planar receiver 100 includes a substantially cylindrical base134 integral with a pair of opposed upright arms 104 forming an upwardlyopen channel 106 between the arms 104 for receiving the elongate rod 90.Each of the receiver arms 104 has an interior face 110 that includes adiscontinuous upper portion of a generally cylindrical central bore 114that extends from the top surfaces 102 of the upright arms 104 at theproximal end 101 of the receiver, downwardly through the open channel106 and the base 134 to a bottom opening 136 at the distal end 139 ofthe multi-planar receiver 100. The channel or upper discontinuousportion of the central bore 114 is bounded on either side by opposingplanar surfaces 112 that curve downwardly into U-shaped lower saddlesurfaces 113, with the opposing planar surfaces 112 and lower saddlesurface 113 defining the front and back ends of the upwardly openchannel 106.

The upper discontinuous portion of the cylindrical central bore 114 hasa partial helically wound guide and advancement structure 116 extendingradially inwardly from the interior face 110 of the channel 106 andlocated adjacent the top surfaces 102 of the arms 104. In theillustrated embodiment, the guide and advancement structure 116 is apartial helically wound interlocking flangeform configured to mate underrotation with a similar structure on the closure 80, as described morefully below. However, it is foreseen that the guide and advancementstructure 116 could alternatively be a square-shaped thread, a buttressthread, a modified buttress thread, a reverse angle thread or otherthread-like or non-thread-like helically wound discontinuous advancementstructure for operably guiding under rotation and advancing the closure80 downward between the arms 104, as well as eventual torqueing when theclosure 80 abuts against the elongate rod 90. Additionally, the variousstructures and surfaces forming the guide and advancement structure 116can be configured to resist, to inhibit, to limit, or to preferentiallycontrol the splay of the upright arms 104 under the rotation andadvancing the closure 80 downward between the arms 104.

The upper discontinuous portion of the cylindrical central bore 114immediately below the guide and advancement structure 116 is defined bya discontinuous cylindrical surface 118 that extends downward from theguide and advancement structure 116 to a positioner chamber portion 128of the receiver cavity 126. Formed into the discontinuous cylindricalsurface 118 is an upper groove 120 spaced below the guide andadvancement structure 116, and a lower groove 122 located between theupper groove 122 and the receiver cavity 126. In one aspect the uppergroove 120 may be deeper and wider than the lower groove 122.

Communicating with and located beneath the channel 106 of themulti-planar receiver 100 at the base portion 134 thereof is the cavity126 having an upper positioner chamber portion 128 and a lower seatingsurface portion 132 located proximate the bottom opening 136. Thepositioner chamber 128 is generally defined by upper non-annular stepsurfaces 125 demarking the bottom of the discontinuous cylindricalsurface 118, a lower non-annular step surface 129, and vertical sidewallsurfaces 127 extending between the step surfaces or between the lowernon-annular step surface 129 and the U-shaped lower saddle surfaces 113of the channel 106. In one aspect the positioner chamber 128 can have anon-round oblong shape with a long axis orientated perpendicular to thelong axis of the open channel, with the upper non-annular step surfaces125 forming undercuts that extend deeper into the interior faces 110 ofthe upright arms 104 than either of the upper and lower grooves 120, 122or the guide and advancement structure 116, thereby forming end spaces130 at opposite ends of the positioner chamber 128. As described in moredetail below, the end spaces 130 are sized and shaped to accommodate thepositioner pieces 172 of the multi-planar two-piece positioner 170 upontheir installation into the multi-planar receiver 100.

The lower seating surface portion 132 of the cavity 126 is spacedslightly below the lower non-annular step surface 129 of the positionerchamber 128 by frusto-conical or chamfer surface 131. Moreover, theseating surface 132 in the multi-planar embodiment of the receiver 100can be a 360 degree continuous partial spherical that is uninterruptedboth across the width and around the circumference thereof. As notedabove, the partial spherical seating surface 132 is sized and shaped forslidably mating with the partial spherical outer surface 74 of theresilient open pivoting multi-planar retainer 70 as well as the upperpartial spherical surface 28 and the lower partial spherical surface 38of the universal shank head 22, and ultimately frictionally mating withthe same outer surfaces 74, 36, as described in greater detail below.

Immediately below the seating surface 132 is a lowermost cylindricalsurface 135 that generally defines the bottom opening 136 thatcommunicates with both the cavity 126 and a receiver lower exterior orbottom 138 of the base 134. The cylindrical surface 135 is substantiallycoaxially aligned with respect to the longitudinal axis 101 of themulti-planar receiver 100. The cylindrical surface 135 is also sized andshaped to be smaller than an outer radial dimension of the multi-planarretainer 70 when the retainer 70 is fixed to the universal shank head22, so as to form a restriction to prevent the retainer 70 and attachedshank head 22 from passing through the cavity 126 and out the lowerexterior 138 of the multi-planar receiver 100 during operation thereof.A bottom frusto-conical or chamfer surface 137 extending between thelowermost cylindrical surface 135 and the bottom surface 138 of thereceiver 110 can provide for increased angulation of the shank 20 aftercapture of the shank head 22 within the receiver cavity 126 by theretainer 70.

An opposed pair of positioner pin apertures 142 extend through thesidewalls of the positioner chamber 128 below the upright arms 104,between the vertical sidewall surfaces 127 and the outer surface of thebase 134. As described in greater detail below, the positioner pinapertures 142 are sized to receive the body portion 194 of a positionerpin 190 in a press-fit engagement upon the installation of thepositioner pin 190 into the positioner chamber 128 together with apositioner piece 172, so as to hold and secure the positioner piece 172in position within the end space 130 of the positioner chamber 128 andagainst the vertical sidewall surfaces 127.

As noted above, the outer surface 108 of the multi-planar receiver 100can have a partially cylindrical and partially faceted outer profile. Inone aspect the faceted or planar portions can include side outer planarfaces 107 on outer surfaces of the upright arms 104 opposite theinterior faces 110 and extending downward to the outer side surfaces ofthe base portion 134. The faceted or planar portions can also includefront and back outer planar faces 109 on the receiver base 134 below theopen channel 106, and which can be oriented perpendicular to the sideouter planar faces 107. In addition, a pair of tool receiving andengaging recesses 140 can be formed into the side outer planar faces 107between each top surface 102 and the pin apertures 142. In one aspectthe tool receiving and engaging recesses 140 can have recessed surfacesthat are parallel with the side outer planar faces 107. The faceted orplanar portions 107, 109 of the outer surface 108 of the multi-planarreceiver 100 and the tool receiving and engaging recesses 140 can servetogether as outer tool engagement surfaces that allow for tooling tomore securely engage and hold the multi-planar receiver 100 during aninitial pre-assembly with the separate open pivoting multi-planarretainer 70, pressure insert 150, and multi-piece positioner 150 intothe multi-planar receiver 100 to form the multi-planar receiversub-assembly 146, as well as during coupling of the receiversub-assembly to the shank 20 after or before the implantation of theshank body 40 into a vertebra, and during further assembly of themulti-planar assembly 10 with the elongate rod 90 and the closure 80.

It is foreseen that other shapes and configurations for the interior andexterior surfaces of the multi-planar receiver 100, different from thoseshown in the drawings while providing for similar interaction andfunctionality of the various components of the pivotal bone anchorassembly, are also possible and considered to fall within the scope ofthe present disclosure. For example, the pressure insert can bepositioned within the receiver in different ways, such as snapped inplace, rotated in place, crimped in place, etc.

Illustrated in FIGS. 13-17 is the pressure insert 150 having a generallycylindrical base 162 with upwardly projecting arms 152 that define aninsert channel 154 that is alignable with the channel 106 of themulti-planar receiver 100 upon installation into the receiver 100, andhaving a width between inner surfaces 155 for operably snugly receivingthe elongate rod 90 between the insert arms 154. In one aspect theinsert arms 152 extend upward to top surfaces 153 that are spaced belowa top surface of an elongate rod 90 when the rod is positioned in theinsert and receiver channels 154, 106. As can be seen in the drawings,an upper curvate rod seating surface 156 extends between lower portionsthe inserts arms 152 and is engageable with the underside surface of theelongate rod 90. The pressure insert 150 also includes anupwardly-concave spherically shaped bottom surface 166 that isconfigured to engage the upper partial spherical surface 28 of theuniversal shank head 22, and to also engage the partial spherical outersurface 74 of the resilient open pivoting retainer 70 at high angulationof the bone anchor 20 relative to the multi-planar receiver 100 (FIG. 69). A central tool receiving aperture 160 can extend vertically throughthe center of pressure insert to allow passage for a driving tool toengage the internal drive feature 24 or drive socket formed into the topof the shank head 22.

Protruding outwardly from the outer side surfaces 157 of the arms 152 ofthe pressure insert 150 are opposing insert ridges 158 that areengageable with the upper grooves 120 formed into the interior faces 110of the receiver upright arms 104 when the receiver sub-assembly is in apre-assembled shipping configuration. The insert ridges 158 aresubsequently engageable with the lower grooves 122 formed into theinterior faces 110 when the pivotal bone anchor assembly is in afriction fit configuration. In one aspect a small rounded relief groove159 can be formed at the junction between the vertical outer sidesurfaces 157 of the insert arms 152 and the top surfaces of the insertridges, for reasons described in more detail below.

The pressure insert 150 further includes opposing skirts 164 that extendoutward from a lower portion of the cylindrical base 162. Each skirt 164includes a partial cylindrical outer surface 163 and a partial annularbottom surface 165 to define a lower skirt edge 167 that is configuredto engage, as described in more detail below, an upper ramp surface thatdefines the top of an upper protrusion extending inwardly from an outerwing portion of a positioner piece.

It is foreseen that other shapes and configurations for the interior andexterior surfaces of the pressure insert, different from those shown inthe drawings while providing for similar interaction and functionalityof the various components of the pivotal bone anchor assembly, are alsopossible and considered to fall within the scope of the presentdisclosure.

Illustrated in FIGS. 18-21 are the multi-planar two-piece positioner 170and positioner pins 190, which are configured to receive and maintainthe multi-planar retainer 70 within the positioner chamber 128 andcentrally aligned along the receiver axis 101 during all phases oftransport and storage of the receiver sub-assembly, as well as duringassembly of the receiver sub-assembly with a mating universal shank head22. The multi-planar positioner 170 generally comprises two multi-planarpositioner pieces 172, with each positioner piece 172 having a centerportion 174 with an upper pin aperture 176 that is used to pin thecenter portion 174 to the vertical sidewall surface 127 of thepositioner chamber 128 with a positioner pin 190, as well as a lowercut-out window 178 below the center portion 174 to provide for greaterflexure of the positioner piece. Each positioner piece 172 furtherincludes bendable outer wing portions 180 on either side of the centerportion 174 that flex outwardly under load or pressure, and which thenspring back inwardly when released. During use the outer wing portions180 are generally bent or flexed outwardly under load or pressureapplied by the retainer 70 from below or by the pressure insert 170 fromabove, with the wing portions 180 then springing back inwardly tocapture and hold the retainer 70 or to abut the outer surface of theinsert 150, respectively. It will be appreciated that the size and shapeof the cut-out window 178 can be varied to control the spring force ofthe outer wing portions 180.

Also shown in the drawings, upper flanges 182 and lower flanges 186project inwardly from the inner face 181 of the outer wing portions 180.The angled tops of the upper flanges 182 define upper ramp surfaces 184while the undersides of the upper flanges 182 define upper retainercapture surfaces 185. Similarly, the angled tops of the lower flanges186 define lower ramp surfaces 188 that also serve as lower retainercapture surfaces. As described in more detail below, the upper retainercapture surfaces 185 of the upper flanges 182 and the lower retainercapture surfaces 188 of the lower flanges 186 loosely define a portionof an open discontinuous retainer capture chamber. In addition, theupper flanges 182 further include upper leading edge contact surfaces183 configured to engage a lower outer surface of the pressure insert170, while the lower flanges 186 include lower leading edge contactsurfaces 187 configured to engage the partial spherical outer surface 74of the resilient open pivoting retainer 70. It is foreseen that othershapes and configurations for the interior and exterior surfaces of themulti-planar two-piece positioner 170, different from those shown in thedrawings while providing for similar interaction and functionality ofthe various components of the pivotal bone anchor assembly, are alsopossible and considered to fall within the scope of the presentdisclosure. For example, the positioner can be of unitary construction.

A positioner pin 190 is provided for each positioner piece 172 of thetwo piece positioner 170. Each positioner pin 190 generally comprises abreak-off pin guide extension 198 at a distal end that guides the pin190 first through the upper pin aperture 176 in the center portion 174of the positioner piece 172, and then into and through the positionerpin aperture 142 that extends through the sidewall of the positionerchamber 128 of the multi-planar receiver 100. Each positioner pin 190further comprises a press-fit body 194 with a cap 192 at a proximal endthat secures the center portion 172 of the positioner piece 172 withinthe positioner chamber 128, once the pin body 194 is pressed into thepositioner pin aperture 142 of the receiver 100. In one aspect a breakoff groove 196 can be cut around the circumference of the pin to definedthe boundary between the break-off pin guide extension 198 and thepress-fit body 194. In addition, it is foreseen that the positionercould be used without break-off pins.

With particular reference to FIGS. 22-23 , the multi-planar embodimentof the resilient open pivoting retainer 70 generally comprises a splitring body 72 defining a central aperture 78, and having a slot or slit77. The slit 77 allows the ring body 72 to expand when pressure isapplied to the inner surface 76, and then to contract back to itsoriginal shape when the pressure is released. As described above, theinner surface 76 of the multi-planar retainer 70 is generally contouredto match the outwardly-facing inner recess surface 34 of the universalshank head 22, which is shown in FIGS. 2-8 as having a curved profilethat gradually curves downwardly and outwardly as moving from the upperledge surface 33 to the lower ledge surface 35. Nevertheless, and asdescribed in more detail below, the inner surface 76 of the multi-planarretainer 70 and the inner recess surface 34 of the universal shank head22 can have complementary contours different from the curved profileselected in the illustrated embodiment of the pivotal bone anchorassembly 10.

The split ring body 72 has a top surface 73, a bottom surface 75, and aspacing between the top and bottom surface 73, 75 that allows themulti-planar retainer 70 to snap in the capture recess 32, with the topsurface 53 adjacent the upper ledge surface 33 and the bottom surface 75adjacent the lower ledge surface 35, upon assembly within the universalshank head 22. In one aspect the diameter of the shaped inner surface 76of the multi-planar retainer 70 can be substantially equal to thediameter of the shaped inner recess surface 34, so that the retainerinner surface 76 engages the recess inner surface 34 with asubstantially neutral fit, with the ring body 72 being neithersubstantially compressed nor substantially expanded after coupling withthe capture recess and subsequent engagement in a friction fit or fullylocked configuration. It will be appreciated by one of skill in the artthat, depending on manufacturing tolerances of the two components, thatthe ring body 72 could be in a slightly loose, slightly expanded, orslightly deformed state after the capturing of the shank head 22 by theretainer 70 within the positioner chamber portion 128 of the receivercavity 126. Nevertheless, the multi-planar retainer 70 is generallydimensioned to be slidably rotatable within the horizontal capturerecess 32 after the shank 20 and retainer 70 are moved downward intocontact with the partial spherical seating surface 132 of themulti-planar receiver 100, but prior to the loading of the multi-planarretainer 70 and universal shank head 22 together in a friction fit orlocked configuration. Thus, even without the retainer rotating on thereceiver partial spherical seating surface, the shank can axially rotatewith respect to the retainer and the receiver.

As described above, the split ring body 72 of the multi-planar retainer70 further includes a partial spherical outer surface 74 having a radiusthat is substantially equal to the radius of the upper partial sphericalsurface 28 and the lower partial spherical surface 38 of the universalshank head 22, so as to form a substantially spherical united universalshank head 22/multi-planar retainer 70 structure when the resilient openpivoting multi-planar retainer 70 is captured or secured within thecapture recess 32. The substantially spherical shape of the uniteduniversal shank head 22/multi-planar retainer 70 structure can be seenin the perspective cut-away view of FIG. 69 showing the fully assembledand locked pivotal bone anchor assembly. For example, with theembodiment of the multi-planar pivotal bone anchor assembly 10illustrated in the drawings, the spherical shape of the united universalshank head 22/multi-planar retainer 70 structure is broken only at thetop by the top annular surface 26 of the shank head and in the midsection by the upper and lower cylindrical surfaces 30, 36 of theuniversal shank head 22. Nevertheless, it is foreseen that other shapesand configurations for the interior and exterior surfaces of themulti-planar resilient open pivoting retainer 70, different from thoseshown in the drawings while providing for similar interaction andfunctionality of the various components of the pivotal bone anchorassembly, are also possible and considered to fall within the scope ofthe present disclosure.

With particular reference to FIGS. 24-25 , the closure 80 comprises agenerally cylindrical closure body 82 having an outer continuous guideand advancement structure 84 formed into the outer side surface of thebody 82, and which operably joins with the guide and advancementstructure 116 formed into the interior face 110 of the receiver arms104. In one aspect the guide and advancement structures 84, 116 can behelically wound flanges with splay-resisting or splay-controlling flangeprofiles for operably guiding under rotation and advancing the closurestructure 80 downward between the arms 104 and having such a nature asto resist or control the splaying of the arms 104 when the closurestructure 80 is advanced into the receiver channel 106. In other aspectsthe guide and advancement structures 84, 116 may take on a variety ofalternative forms, including but not limited to a buttress thread, asquare thread, a reverse angle thread, or other thread like ornon-thread like helically wound advancement structure. The closure body82 can also include a substantially planar bottom surface 83 below theguide and advancement structure 84 for directly engaging a top surfaceportion of the elongate rod.

Also shown in the drawings, a break-off tab 88 can be attached the upperend 81 of the closure body 82 and extend upwardly away therefrom toprovide an external tool engagement structure 89 that can be used forrotatably advancing the closure downward between the arms 104 of themulti-planar receiver 100. In one aspect the break-off tab 88 can bedesigned to allow the tab 88 to break from the closure body 82 at apreselected torque, for example, 60 to 140 inch pounds.

Below and surrounded by the break-off tab 88, the upper end 81 of theclosure 80 can further include an internal tool engagement structure,such as internal drive socket 86, which extends downward or inward intothe closure body 82. The internal drive socket 86 can be used forclosure removal. Similar to the internal drive socket formed into theshank head, the internal socket 86 of the illustrated closure 80 is anaperture formed in the upper end 81 and has a hex shape designed toreceive a hex tool (not shown) of an Allen wrench type, into theaperture for rotating and driving the closure body 82. It will beappreciated that the internal tool engagement structure, in thealternative, may take a variety of tool-engaging forms, and may includeone or more apertures of various shapes, such as a pair of spaced apartapertures or a multi-lobular or star-shaped aperture, such as those soldunder the trademark TORX, or the like. It is further foreseen thatclosures having other shapes, configurations, and thread forms,different from those shown in the drawings while providing for similarinteraction and functionality of the various components of the pivotalbone anchor assembly, are also possible and considered to fall withinthe scope of the present disclosure.

With reference to FIG. 26 , the multi-planar receiver 100, themulti-planar positioner 170 and positioner pins 180, the multi-planarretainer 70, and the pressure insert 150 are generally assembledtogether into a receiver sub-assembly at a factory setting that includestooling for holding, alignment and manipulation of the component pieces.In some circumstances, the shank 20 is also assembled with the receiversub-assembly at the factory. In other instances, it is desirable tofirst implant the shank 20, followed by addition of the pre-assembledreceiver sub-assembly at the insertion point (see, e.g., FIGS. 45-46 ).In this way, the surgeon may advantageously and more easily implant andmanipulate the shanks 20, distract or compress the vertebrae with theshanks and work around the shank upper portions or shank heads withoutthe cooperating receivers being in the way. In other instances, it isdesirable for the surgical staff to pre-assemble a shank of a desiredsize and/or variety (e.g., having a cannulated shank body, differentthread patterns on the shank body, and/or hydroxyapatite on the shankbody 40), with the receiver sub-assembly prior to implantation of theshank 20 into a patient's vertebra. Allowing the surgeon to choose theappropriately sized, type, or treated shank 20 advantageously reducesinventory requirements, thus reducing overall cost.

The pre-assembly of the multi-planar receiver 100, the multi-planartwo-piece positioner 170 and positioner pins 180, the multi-planarretainer 70, and the pressure insert 150 into a receiver sub-assembly146 is shown in FIGS. 27-44 . With particular reference to FIG. 27 ,first the retainer 70 is inserted into the receiver open channel 106leading with the outer surface 74, with the retainer top surface 73facing one arm 104 and the retainer bottom surface 75 facing theopposing arm 104. The retainer 70 is then lowered in such sidewaysmanner, parallel with the receiver channel 106, through the channel 106and into the receiver cavity 126 to the partial spherical seatingsurface 132 proximate the receiver bottom opening 136. The multi-planarretainer 70 is then rotated or allowed to rotate downward until itsouter surface 74 rests against the receiver partial spherical seatingsurface 132, generally with the top surface 73 facing upwardly and thebottom surface 75 facing downwardly. (FIGS. 28-29 ).

After reaching the receiver partial spherical seating surface 132, themulti-planar retainer 70 is then rotated back up into a verticalposition, but one that is now perpendicular to the receiver channel 106.One at a time, each positioner piece 172 of the multi-planar two-piecepositioner 170 is then downloaded around the upright retainer 70 andinto one of the opposing end spaces 130 of the positioner chamber 128.(FIGS. 30-32 ). The multi-planar retainer 70 can then rotated back intothe horizontal position resting against the receiver partial sphericalseating surface 132, with the top surface 73 facing upwardly and thebottom surface 75 facing downwardly. Each multi-planar positioner piece172 is then mounted or secured with the positioner chamber 128 bypressing a positioner pin 190 first through the upper pin aperture 176in the center portion 174 of the positioner piece 172, and then into andthrough a positioner pin aperture 142 that extends through the sidewallof the positioner chamber 128 of the multi-planar receiver 100. (FIGS.33-34 ). The end caps 192 of the positioner pins 190 will then engagethe center portions 174 of the positioner pieces 172 to hold the centerportions against the vertical sidewall surfaces 127 of the end spaces130, thereby securing the positioner pieces 172 in place within thepositioner chamber 128. Optionally, the break-off pin guide extensions198 of the positioner pins 190 can now be sheared or broken off at thebreak-off groove 196.

With both the multi-planar retainer 70 and the two-piece multi-planarpositioner 170 now in their initial respective pre-loaded positions, thepressure insert 150 can be positioned above the multi-planar receiver100 and rotated until the opposing insert skirts 164 become aligned withthe receiver channel 106. The pressure insert 150 is then moveddownwardly through the receiver channel 106 toward the positioner 170(FIGS. 35-36 ) until the bottom edges 167 of the skirts 164 rest againstthe ramp surfaces 184 of the upper flanges 182 of the positioner pieces172 (FIGS. 37-38 ). In this intermediate position the insert ridges 158projecting outward from the insert arms 152 may be located slightlyabove the upper receiver grooves 120 formed into the discontinuouscylindrical surface 118 of the interior face 110 of the receiver arms104.

The pressure insert 150 can then be pushed downwardly to expand the wingportions 180 of the multi-planar positioner pieces 172 outwardly towardthe vertical sidewall surfaces 127 of the end spaces 130 and to alignthe insert ridges 158 with the upper receiver grooves 120. The insert150 is then rotated around the receiver central longitudinal axis untilthe insert ridges 158 begin to slide into the upper receiver grooves 120and the opposing insert skirts 164 begin to slide under the non-annularupper step surface 125 that defines the top of the positioner chamber128. (FIGS. 39-40 ). The rotation of the insert continues until theopposing insert skirts 164 slide off the ramp surfaces 184 of the upperpositioner flanges 182 and clock into position adjacent the centerportions 174 of the positioner pieces 172, allowing the positioner wingportions 180 to snap back and lock the insert skirts 164 against furtherrotation with the inside surfaces of the upper positioner flanges 182.(FIGS. 41-42 ). In this position the leading edges 187 (FIG. 19 ) of thelower positioner flanges 186 abut the outer surface 74 of themulti-planar retainer 70, generally above the hemisphere line of thepartial spherical surface 74. The insert ridges 158 are also fullyenclosed within the upper receiver grooves 120 to prevent furthervertical movement of the pressure insert 150 until pressed downward witha deployment tool.

In a final pre-assembly step the multi-planar retainer 70 is pushedupward toward the pressure insert 150, causing the positioner wingportions 180 to again flex outward while allowing the leading loweredges 187 to slide downward over and off the retainer partial sphericalsurface outer surface 74. This allows the angled lower retainer capturesurfaces 188 (FIG. 19 ) of the lower positioner flanges 186 to engagethe bottom edge of the retainer outer surface 74 while the wing portions180 of the positioner pieces 172 snap back with a spring forcedetermined by the positioner center portions 174. The resultinginteraction drives the retainer 70 upward against the upper retainercapture surfaces 185 of the upper flanges 182 so as to fully to capturethe retainer between the upper retainer capture surfaces 185 and thelower retainer capture surfaces 188 of the lower flanges 186, as shownin FIGS. 43-44 .

The multi-planar receiver 100, the two-piece multi-planar positioner 170and positioner pins 180, the multi-planar retainer 70, and the pressureinsert 150 are now pre-assembled into the receiver sub-assembly 146shown in FIGS. 43-44 and 45-46 . If the break-off pin guide extensions198 of the positioner pins 190 have not yet been sheared or broken offat the break-off groove 196, this action may be performed afterpre-assembly is complete to leave the receiver sub-assembly 146 with asmooth outer surface suitable for storage, shipping, and eventually usein a surgical setting.

The multi-planar receiver sub-assembly 146 is now in its shippingconfiguration, in which the multi-planar retainer 70 is securelysupported and maintained within the positioner chamber portion 128 ofthe receiver cavity 126 by the two-piece multi-planar positioner 170,with the retainer 70 being centralized and controlled in space aboveboth the receiver bottom opening 136 and the partial spherical seatingsurface 132. In the shipping configuration the pressure insert 150 isalso held in its vertical position within the receiver central bore 114by the insert ridges 158 being fully enclosed with the receiver uppergrooves 120 that are sized and shaped to prevent any upward movement ofthe pressure insert 150 relative to the multi-planar receiver 100, andto allow for downward movement or deployment of the pressure insert 150only with considerable direct force that may be provided by theappropriate tooling. Furthermore, in the shipping configuration thepressure insert 150 is also held or ‘clocked’ in angular position by theinner surfaces of the upper flanges 182 that project inwardly from thepositioner wing portions 180 to surround the opposing skirts 164 thatproject outwardly from the insert base 162.

Illustrated in FIGS. 45-69 is the assembly or coupling of thepre-assembled receiver sub-assembly 146 of the multi-planar pivotal boneanchor assembly 10 to a universal shank head 22 that optionally may havea horizontal capture recess 32 that is protected with the removablecapture recess protection sleeve 50 described above. It will beunderstood that the capture recess protection sleeve 50 may be removedfrom the shank head 22 either prior to installing the sub-assembly 146over the shank head 22 or during the installation of the sub-assembly146 to the shank head 22, as shown below.

With reference first to FIGS. 45-46 , the pre-assembled multi-planarreceiver sub-assembly 146 is positioned above the universal shank head22, with the receiver bottom opening 136 generally aligned with theshank head upper partial spherical surface 28.

With reference to FIGS. 47-48 , the multi-planar receiver sub-assembly146 is then dropped until the upper partial spherical surface 28 and theupper cylindrical outer surface 30 of the universal shank head 22 enterthe receiver bottom opening 36. At this point the receiver bottomsurface 138 also abuts the top surface 53 of the capture recessprotection sleeve 50.

With reference to FIGS. 49-50 , the multi-planar receiver sub-assembly146 is further moved or pushed downward (or the universal shank head 22is moved upward, depending on the frame of reference of the reader)until the shank head upper partial spherical surface 28 contacts theinner surface 76 of the multi-planar retainer 70. At the same time thecapture recess protection sleeve 50 can be pushed downward off theuniversal shank head 22 to the neck region 42 of the bone anchor,exposing the capture recess 32 only after it has entered the receivercavity 126 through the bottom opening 136. At this point the capturerecess protection sleeve 50 can be entirely removed from themulti-planar assembly 10.

With reference to FIGS. 51-52 , the multi-planar receiver sub-assembly146 continues downward (or the universal shank head 22 upward) so thatfirst the shank head upper partial spherical surface 28, and then theshank upper cylindrical outer surface 30, bears against the curvateinner surface 76 of the multi-planar retainer 70, causing the expansionof both the retainer 70 and its supporting multi-planar positioner 170until the retainer 70 reaches maximum expansion with a narrowestdiameter of the curvate inner surface 76 bearing against the shank uppercylindrical outer surface 30.

With reference to FIGS. 53-54 , the multi-planar receiver sub-assembly146 then continues downward (or the universal shank head 22 upward)until the shank head 22 reaches max push-through in which the shank headupper partial spherical surface 28 abuts the concave bottom surface 166of the pressure insert 150 and the retainer curvate inner surface 76bears against the shank lower cylindrical outer surface 36.

With reference to FIGS. 55-66 , the multi-planar receiver sub-assembly146 is then pulled or moved back upward (or the universal shank head 22back downward) until the multi-planar retainer 70 snaps into and iscaptured by the horizontal capture recess 32, with the retainer curvateinner surface 76 engaged with the outwardly-facing inner recess surface34 of the shank head 22.

With reference to FIGS. 57-58 , the multi-planar receiver sub-assembly146 then continues back upward (or the universal shank head 22 backdownward) while the multi-planar retainer 70 disengages from themulti-planar positioner 70 (which is vertically constrained by the upperand lower step surfaces 25, 29 of the positioner chamber 128) andbecomes seated on the 360° continuous partial spherical seating surface132 of the multi-planar receiver 100.

With reference to FIGS. 59-60 , the pressure insert 150 can now bedownwardly deployed with tooling to a non-floppy friction fit. Forexample, a deployment tool can be applied to the upper curvate rodseating surface 156 to push the insert ridges 158 downward out of theupper receiver grooves 20 and onto the discontinuous cylindrical surface118 of the central bore 114 of the receiver, where the ridges 158encounter an interference fit that resists the downward motion. In oneaspect the force required to initially move the pressure insert and toovercome this interference fit can be about 200 pounds-force or greater.This action can temporarily cause the upwardly-projecting arms 152 ofthe pressure insert 150 to deflect inward, closing the gap at the top ofthe insert channel 154. With the pressure insert 150 in thispartially-deployed position, a skilled artisan would recognize that theelongate rod may not fit within the insert channel 154.

Additional details and disclosure regarding deployment tools or toolingfor preparing, assembling, and/or deploying bone screws and pivotal boneanchor assemblies or components thereof during spinal surgery, includingthe receiver sub-assembly and the bone anchor or shank having auniversal shank head described above, can be found in co-pending PatentCooperation Treaty (PCT) Application PCT/US2019/051190, filed the sameday as the present application on Sep. 13, 2019, and claiming thebenefit of U.S. Provisional Application No. 62/731,059, filed Sep. 13,2018, with each of the above-referenced applications being incorporatedby reference in its entirety herein and for all purposes.

With reference to FIGS. 61-64 , the downward driving of the pressureinsert 150 with the deployment tool can continue until the insert ridges158 snap into the lower receiver grooves 122, at which point the insertconcave spherical bottom surface 166 also fully engages the shank headupper partial spherical surface 28 and the retainer outer partialspherical surface 74 also fully engages the receiver partial sphericalseating surface 132 to establish a friction fit. The friction fit firmlyholds the multi-planar receiver 100 to the universal shank head 22 whileallowing for movement of the receiver 100 relative to the bone anchor 20with an applied force. Furthermore, with the pressure insert 150 in thedeployed position, the leading edges 183 (FIG. 19 ) of the upper flanges182 of the multi-planar positioner piece 172 can abut the cylindricalouter surface of the insert base 162 to hold the positioner piece 172 inan expanded position with the lower flanges 186 well-spaced from thenow-pivotable multi-planar retainer 70 and universal shank head 22.(FIGS. 63-64 ).

With reference to FIGS. 65-66 , the friction fit engagement of themulti-planar receiver sub-assembly 146 to the bone anchor 20 can providethe surgeon or medical professional with a number of alignment options.For example, the friction fit allows for rotation of the multi-planarreceiver 100 around the universal shank head 22, with an applied axialtwisting force, as well as angulation of the receiver 100 relative theshank head 22, with an applied tangential moment force, so as to alignthe receiver channel 106 with the receiver channels of an adjacent boneanchor assembly.

The friction fit is provided from above by sliding frictional engagementbetween the insert concave spherical bottom surface 166 and the shankhead upper partial spherical surface 28 and/or the retainer outerpartial spherical surface 74, and from below by sliding frictionalengagement between the receiver partial spherical seating surface 132and the retainer outer partial spherical surface 74 and/or the shankhead lower partial spherical surface 38.

With reference to FIGS. 67-69 , the full assembly of an elongate rod 90and a closure 80 to the multi-planar receiver sub-assembly 46 may now beaccomplished. First, after a desired alignment and/or positioning of thereceiver sub-assembly 146 to the bone anchor 20 has been achieved, theelongate rod 90 can then be installed (i.e., reduced) into the receiverchannel 106 until the underside surface of the rod 90 engages the uppercurvate rod seating surface 156 of the insert channel 154. The closure80 can then be installed into the upper portion of the receiver centralbore 114, in which the continuous guide and advancement structure 84 ofthe closure body 82 engages the discontinuous guide and advancementstructure 116 formed into the interior faces 110 of the receiver uprightarms 104.

The closure 80 can be threaded downwardly until the bottom surface 83 ofthe closure body 82 engages a top surface of the elongate rod 90.Further rotation/torqueing of the closure 80 can then be used to drivethe elongate rod 90 downward into the pressure insert 150, which in turndrives the universal shank head 22 and multi-planar retainer 70 downwardinto the receiver partial spherical seating surface 132 to achieve afinal locking of the multi-planar pivotal bone anchor assembly 10, inwhich the receiver sub-assembly 146 can no longer move relative to thebone anchor 20.

With reference to FIG. 69 , the closure break-off tab 88 can be shearedfrom the closure body 42 at a pre-determine torque value, therebyensuring that the pivotal bone anchor assembly 10 is fully locked.

As noted above, the outwardly-facing inner recess surface of the capturegroove formed into the universal shank head can include any one of avariety of profiles that are different from that curved profile of theinner recess surface 34 illustrated in FIGS. 2-8 . With brief referenceto FIGS. 70-72 , for example, in one alternative embodiment the boneanchor or shank 200 may have a universal shank head 202 with an upperledge surface 205, a lower ledge surface 207, and an inner recesssurface 206 that together define a circumferential horizontal capturerecess 204, with the outwardly-facing inner recess surface 206 having acylindrical profile. The capture recess 204 is therefore configured forengagement with a resilient open retainer, such as multi-planar retainer210, having a split ring body 212 defining a central aperture 218 andhaving a slit or slot 217 formed therethrough, a partial spherical outersurface 214, and an inner surface 216 also having cylindrical profile tomatch the profile of the inner recess surface 206 of universal shankhead 202.

Similarly, and with reference to FIGS. 73-75 , for example, in yetanother embodiment the bone anchor or shank 220 may have a universalshank head 222 with an upper ledge surface 225, a lower ledge surface227, and an inner recess surface 226 that together define acircumferential horizontal capture recess 224, with the outwardly-facinginner recess surface 226 having a conical or frustoconical profile. Thecapture recess 224 is thus configured for engagement with a resilientopen retainer, such as multi-planar retainer 230, having a split ringbody 232 defining a central aperture 238 and having a slit or slot 237formed therethrough, a partial spherical outer surface 234, and an innersurface 236 also having conical or frustoconical profile to match theprofile of the inner recess surface 226 of universal shank head 222.

It is foreseen that other profile shapes and configurations for thecomplementary outwardly-facing inner recess surface of the universalshank head and the interior surface of the resilient open pivotingretainer (whether multi-planar or other) that are different from thoseshown in the drawings, while providing for similar interaction andfunctionality of the various components of the pivotal bone anchorassembly, are also possible and considered to fall within the scope ofthe present disclosure.

With reference now to FIG. 76 , illustrated therein is anotherrepresentative embodiment of the present disclosure, namely a uni-planarpivotal bone anchor apparatus or assembly 250 (hereinafter referenced toas “the uni-planar assembly 250”) for securing an elongate rod topatient bone in spinal surgery. The uni-planar assembly 250 is similarto the multi-planar assembly 10 described above, but with modificationsto the receiver, pivoting retainer, and positioner components that serveto restrict the motion of the shank 20 relative to the receiver 300 to asingle plane.

In particular, the uni-planar assembly 250 can include the same boneanchor or shank 20 that is included in the multi-planar assembly 10,with the shank 20 having the universal shank head 22 at a proximal endand an anchor portion or shank body 40 extending distally from the shankhead 22 for securement to patient bone. As previously described inreference to the multi-planar embodiment, the structure of the universalshank head 22 having the circumferential horizontal capture recess 32,as shown above in FIGS. 2-4 , allows for the shank head 22 to connectwith either a multi-planar or a uni-planar receiver sub-assembly, and inparticular with either a multi-planar or a uni-planar retainer which isengageable with a complementary multi-planar or uni-planar pivotingreceiver, respectively. This feature of the pivotal bone anchor assemblysystem can advantageously provide for selectable multi-planar oruni-planar motion of a receiver with respect to the universal shank head22, as determined by a surgeon in an operating environment afterimplantation of the shank body 40 into a vertebra, but prior to thecoupling or capture of the universal shank head 22 with a receiversub-assembly.

As shown in FIG. 76 , the uni-planar assembly 250 also includes auni-planar receiver 300 having an internal cavity 326 in a base portion334 and two upright arms 304 extending upwardly from the base portion334 to define a rod channel 306 for receiving the elongate rod 90. Theuni-planar receiver 300 can also be initially pivotably secured to theuniversal shank head 22 with a number of separate internal componentsthat have been pre-assembled into the internal cavity 326 and the rodchannel 306 to form a uni-planar receiver sub-assembly. These componentscan include a uni-planar resilient open retainer 270, a pressure insert150 as previously described, and a uni-planar multi-piece positioner 370that may be secured within the internal cavity 326 of the base portion334 with positioner pins 390. After the elongate rod 90 has beenpositioned within a lower portion of the rod channel 306, the closure 80as previously described can be threadably secured into an upper portionof the rod channel to apply pressure to an upper surface of the elongaterod 90, thereby locking both the elongate rod 90 and the uni-planarassembly 250 into a final locked position.

Also shown in FIG. 76 , in one aspect the bone anchor or shank 220 ofthe uni-planar assembly 250 can include the optional removable resilientcapture recess protection sleeve 50 installed within the horizontalcapture recess 32 formed into the universal shank head 22, so as toprevent soft tissue and bone chips from entering and fouling the capturerecess prior to introduction of the shank head 22 into the uni-planarreceiver sub-assembly.

The uni-planar receiver 300 modified for use within the uni-planarassembly 250 is shown in FIGS. 77-78 . The uni-planar receiver 300 issimilar to the multi-planar receiver described above, having a baseportion 334 defining and internal cavity 326 and two upright arms 304extending upwardly from the base portion 334 to define a rod channel 306for receiving the elongate rod 90. The internal cavity 326 of theuni-planar receiver 300 also includes an upper positioner chamber 328configured to receive and secure the multi-piece or two-piece uni-planarpositioner 370, and a lower seating surface 332 located proximate thebottom opening 336 and configured to slidably frictionally engage withthe outer surface 274 of the uni-planar retainer 270 in the friction fitconfiguration described in more detail below.

The lower seating surface 332 is modified, however, to include twoopposed recesses or pockets 333 for receiving a pair of rounded pegs 279that project laterally outward from the uni-planar retainer's 270 outersurface 274 (FIGS. 79-80 ). The opposed pockets 333 are contoured with arounded internal surface complementary with the rounded outer surface ofthe pegs 279, and also aligned relative to the non-continuouscircumferential partial spherical lower seating surface 332. Thisprovides for the retainer's non-continuous circumferential partialspherical outer surface 274 to fictionally slide over the receiver'snon-continuous circumferential partial spherical lower seating surface332 while the opposed rounded pegs 279 of the retainer 270 rotate orpivot within the opposed pockets 333 of the receiver cavity 326.

It is foreseen that other shapes and configurations for the interior andexterior surfaces of the uni-planar receiver 300, different from thoseshown in the drawings while providing for similar interaction andfunctionality of the various components of the pivotal bone anchorassembly, are also possible and considered to fall within the scope ofthe present disclosure.

The uni-planar retainer 270 modified for use within the uni-planarassembly 250 is shown in FIGS. 79-80 . The uni-planar retainer 270 issimilar to the multi-planar retainer described above, having a splitring body 272 defining a central aperture 278, and having a slot or slit277 allows the ring body 272 to expand when pressure is applied to theinner surface 276, and then to contract back to its original shape whenthe pressure is released. The split ring body 272 has a top surface 273,a bottom surface 275, and a spacing between the top and bottom surface273, 275 that allows the retainer 270 to snap in the capture recess 32,with the top surface 273 adjacent the upper ledge surface 33 and thebottom surface 275 adjacent the lower ledge surface 35, upon assemblywithin the universal shank head 22. As with the multi-planar embodiment,the diameter of the shaped inner surface 276 of the uni-planar retainer270 can be substantially equal to the diameter of the shaped innerrecess surface 34, so that the retainer inner surface 276 engages therecess inner surface 34 with a substantially neutral fit, with the ringbody 272 being neither substantially compressed nor substantiallyexpanded after coupling with the capture recess and subsequentengagement in a friction fit or fully locked configuration. Theuni-planar retainer 270 is also dimensioned to be slidably rotatablewithin the horizontal capture recess 32 after the shank 20 anduni-planar retainer 270 are moved downward into contact with the partialspherical seating surface 332 of the uni-planar receiver 300, but priorto the loading of the retainer 270 and shank head 22 together in afriction fit or locked configuration.

As with the multi-planar embodiment, the split ring body 272 of theuni-planar retainer 270 includes a partial spherical outer surface 274having a radius that is substantially equal to the radius of the upperpartial spherical surface 28 and the lower partial spherical surface 38of the shank head 22, so as to form a substantially spherical shank head22/uni-planar retainer 270 structure when the resilient open retainer270 is captured or secured within the capture recess 32. The split ringbody 272 has been modified in the uni-planar embodiment, however, toinclude the two opposing rounded pegs 279 extending outward from thepartial spherical outer surface 274 and configured for engagement withinthe opposed pockets 333 in the receiver cavity 326 of the uni-planarreceiver 300. As described in more detail below, the engagement betweenthe retainer pegs 279 with the receiver pockets 333 limits the pivotingmotion of the shank 20 relative to the uni-planar receiver 300 to asingle plane, with the axis of rotation being defined by the opposedretainer pegs 279.

The substantially spherical shape of the united universal shank head22/uni-planar retainer 270 structure can be seen in the perspectivecut-away view of FIG. 124 showing the fully assembled and lockeduni-planar pivotal bone anchor assembly 250. For example, the sphericalshape of united shank head 22/uni-planar retainer 270 structure isbroken only at the top by the top annular surface 26 of the shank head,in the mid section by the upper and lower cylindrical surfaces 30, 36 ofthe shank head 22, and on the sides by the outwardly-projecting roundedpegs 279 of the uni-planar retainer 270. Nevertheless, it is foreseenthat other shapes and configurations for the interior and exteriorsurfaces of the uni-planar resilient open retainer 270, different fromthose shown in the drawings while providing for similar interaction andfunctionality of the various components of the pivotal bone anchorassembly, are also possible and considered to fall within the scope ofthe present disclosure

The uni-planar two-piece positioner 370 modified for use within theuni-planar assembly 250 is shown in FIGS. 81-82 . The uni-planarpositioner 370 is similar to the multi-planar positioner 170 describedabove, comprising the two positioner pieces 372, with each positionerpiece 372 having a center portion 374 with an upper pin aperture 376that is used to pin the center portion 374 to the vertical sidewallsurface 327 of the positioner chamber 326 with a positioner pin 390, aswell as the lower cut-out window 378 below the center portion 374 toprovide for greater flexure of the positioner piece. The lower cut-outwindow 378 has been modified in the uni-planar embodiment to accommodatethe retainer pegs 279 during expansion of the uni-planar retainer 270.

As with the multi-planar embodiment, each positioner piece 372 furtherincludes bendable outer wing portions 380 on either side of the centerportion 374 that flex outwardly under load or pressure, and which thenspring back inwardly when released. The wing portions 380 of theuni-planar embodiment also include upper flanges 382 and lower flanges386 projecting inwardly from the inner faces of the outer wing portions180 to define, among other features, an open discontinuous retainercapture chamber. It is foreseen that other shapes and configurations forthe interior and exterior surfaces of the uni-planar two-piecepositioner 370, different from those shown in the drawings whileproviding for similar interaction and functionality of the variouscomponents of the pivotal bone anchor assembly, are also possible andconsidered to fall within the scope of the present disclosure.

The pre-assembly of the uni-planar receiver 300, the uni-planartwo-piece positioner 370 and positioner pins 380, the uni-planarretainer 270, and the pressure insert 150 into a uni-planar receiversub-assembly is shown in FIGS. 83-97 . With particular reference to FIG.84 , first the retainer 270 is inserted into the receiver open channel306 leading with the outer surface 274, with the top surface 273 facingone arm 304 and the retainer bottom surface 275 facing the opposing arm304. The retainer 270 is then lowered in such sideways manner, parallelwith the receiver channel 306, through the channel 306 and into thereceiver cavity 326 to the partial spherical seating surface 332proximate the receiver bottom opening 336. The retainer 270 is thenrotated or allowed to rotate downward until its outer surface 274 restsagainst the receiver partial spherical seating surface 332 and theopposed rounded pegs 279 of the uni-planar retainer 270 are receivedwithin the opposed pockets 333 formed into the seating surface 332 ofthe uni-planar receiver 300, and generally with the retainer top surface273 facing upwardly and the bottom surface 275 facing downwardly. (FIGS.85-86 ).

After reaching the receiver partial spherical seating surface 332, theuni-planar retainer 270 is then rotated on the opposed rounded pegs 279back up into a vertical position, but one that is now perpendicular tothe receiver channel 306. One at a time, each positioner piece 372 ofthe uni-planar two-piece positioner 370 is then downloaded around theupright retainer 270 and into one of the opposing end spaces 330 of thepositioner chamber 328. (FIGS. 87-89 ). During the downloading of thepositioner pieces 372 the opposed pegs 279 are received with theenlarged cut-out windows 378 formed into the center portions of eachpositioner piece of the uni-planar embodiment. As discussed above, theenlarged cut-out windows 378 (FIG. 82 ) are sized and shaped to provideclearance for the retainer pegs 279 during all subsequent steps in thepre-assembly of the components into the uni-planar receiversub-assembly, as well as all subsequent mounting and deployment steps incoupling the uni-planar receiver sub-assembly to the universal shankhead 22.

The uni-planar retainer 270 can then be rotated back into the horizontalposition resting against the receiver partial spherical seating surface332, with the top surface 273 facing upwardly and the bottom surface 275facing downwardly. Each positioner piece 372 is then mounted or securedwith the positioner chamber 328 by pressing a positioner pin 390 firstthrough the upper pin aperture 376 in the center portion 374 of thepositioner piece 372, and then into and through a positioner pinaperture 342 that extends through the sidewall of the positioner chamber328 of the uni-planar receiver 300. (FIGS. 89-90 ). The end caps 392 ofthe positioner pins 390 will then engage the center portions 374 of thepositioner pieces 372 to hold the center portions against the verticalsidewall surfaces 327 of the end spaces 330, thereby securing thepositioner pieces 372 in place within the positioner chamber 328.Optionally, the break-off pin guide extensions 398 of the positionerpins 390 can now be sheared or broken off at the break-off groove 396.

With both the uni-planar retainer 270 and the uni-planar two-piecepositioner 370 now in their initial respective pre-loaded positions, thepressure insert 150 can be positioned above the multi-planar receiver300 and rotated until the opposing insert skirts 164 become aligned withthe receiver channel 306. The pressure insert 150 is then moveddownwardly through the receiver channel 306 toward the positioner 370(FIGS. 92-93 ), until the bottom edges 167 of the skirts 164 restagainst the ramp surfaces 384 of the upper flanges 382 of the positionerpieces 372 (FIGS. 94-95 ). In this intermediate position the insertridges 158 projecting outward from the insert arms 152 may be locatedslightly above the upper receiver grooves 320 formed into discontinuouscylindrical surface 318 of the interior face 310 of the insert arms 304.

The pressure insert 150 can then be pushed downwardly to expand the wingportions 380 of the positioner pieces 372 outwardly toward the verticalsidewall surfaces 327 of the end spaces 330 and to align the insertridges 158 with the upper receiver grooves 320. The insert 150 is thenrotated around the receiver central longitudinal axis until the insertridges 158 begin to slide into the upper receiver grooves 320 and theopposing insert skirts 364 begin to slide under the non-annular upperstep surface 325 that defines the top of the positioner chamber 328.(FIGS. 96-97 ). The rotation of the pressure insert 150 continues untilthe opposing insert skirts 164 slide off the ramp surfaces 384 of theupper positioner flanges 382 and clock into position adjacent the centerportions 374 of the positioner pieces 372, allowing the positioner wingportions 380 to snap back and lock the insert skirts 164 against furtherrotation with the inside surfaces of the upper positioner flanges 382.(FIGS. 98-99 ). In this position the leading edges 387 of the lowerpositioner flanges 386 abut the outer surface 274 of the retainer 270,generally above the hemisphere line of the partial spherical surface274. The insert ridges 158 are also fully enclosed within the upperreceiver grooves 320 to prevent further vertical movement of thepressure insert 150 until pressed downward with a deployment tool.

In a final pre-assembly step the uni-planar retainer 270 is pushedupward toward the pressure insert 150, causing the positioner wingportions 380 to again flex outward while allowing the leading loweredges 387 (FIG. 82 ) to slide downward over and off the retainer partialspherical surface outer surface 274. This allows the angled lowerretainer capture surfaces 388 of the lower positioner flanges 386 toengage the bottom edge of the retainer outer surface 274 while the wingportions 380 of the positioner pieces 372 snap back with a spring forcedetermined by the positioner center portions 374. The resultinginteraction drives the retainer 270 upward against the upper retainercapture surfaces 385 of the upper flanges 382 so as to fully to capturethe retainer between the upper retainer capture surfaces 385 and thelower retainer capture surfaces 388 of the lower flanges 386, as shownin FIGS. 100-101 . During the upward movement of the retainer 270 theinner edges of the positioner piece cut-out windows 378 can operate tosurround the outwardly projecting opposed pegs 279 of the uni-planarretainer 270 to maintain their alignment over the opposed pockets 333formed into the seating surface 332 of the uni-planar retainer 300.

The uni-planar receiver 300, the uni-planar two-piece positioner 370 andpositioner pins 380, the uni-planar retainer 270, and the pressureinsert 150 are now pre-assembled into the uni-planar receiversub-assembly 346 shown in FIGS. 100-101 and 102-103 . If the break-offpin guide extensions 398 of the positioner pins 390 have not yet beensheared or broken off at the break-off groove 396, this action may beperformed after pre-assembly is complete to leave the receiversub-assembly 346 with a smooth outer surface suitable for storage,shipping, and eventually use in a surgical setting.

The uni-planar receiver sub-assembly 346 is now in its shippingconfiguration, in which the uni-planar retainer 270 is securelysupported and maintained within the positioner chamber portion 328 ofthe receiver cavity 326 by the uni-planar two-piece positioner 370, withthe retainer 270 being centralized in space above both the receiverbottom opening 336 and the partial spherical seating surface 332. In theshipping configuration the pressure insert 150 is also held in itsvertical position within the receiver central bore 314 by the insertridges 158 being fully enclosed with the receiver upper grooves 320 thatare sized and shaped to prevent any upward movement of the pressureinsert 150 relative to the uni-planar receiver 300, and to allow fordownward movement or deployment of the pressure insert 150 only withconsiderable direct force that may be provided by the appropriatetooling. Furthermore, in the shipping configuration the pressure insert150 is also held or ‘clocked’ in angular position by the inner surfacesof the upper flanges 382 that project inwardly from the positioner wingportions 380 to surround the opposing skirts 164 that project outwardlyfrom the insert base 162.

Illustrated in FIGS. 102-124 is the assembly or coupling of thepre-assembled receiver sub-assembly 346 of the uni-planar pivotal boneanchor assembly 250 to a universal shank head 22 that, optionally, doesnot also include the removal of the capture recess protection sleeve 50described above.

With reference first to FIGS. 102-103 , the pre-assembled uni-planarreceiver sub-assembly 346 is positioned above the universal shank head22, with the receiver bottom opening 336 generally aligned with theshank head upper partial spherical surface 28.

With reference to FIGS. 104-105 , the uni-planar receiver sub-assembly346 is then dropped until the upper partial spherical surface 28 and theupper cylindrical outer surface 30 of the bone anchor enter the receiverbottom opening 336.

With reference to FIGS. 106-107 , the uni-planar receiver sub-assembly346 is then moved or pushed downward (or the universal shank head ismoved upward, depending on the frame of reference of the reader) untilthe shank head upper partial spherical surface 29 contacts the contactsthe inner surface 276 of the uni-planar retainer 270.

With reference to FIGS. 108-109 , the receiver sub-assembly 346continues downward (or the universal shank head upward) so that firstthe shank head upper partial spherical surface 28, and then the shankupper cylindrical outer surface 30, bears against the curvate innersurface 276 of the uni-planar retainer 270, causing the expansion ofboth the retainer 270 and its supporting positioner 370 until theretainer 270 reaches maximum expansion with a narrowest diameter of thecurvate inner surface 276 bearing against the shank upper cylindricalouter surface 30.

With reference to FIGS. 110-111 , the receiver sub-assembly 346 thencontinues downward (or the shank head upward) until the shank head 22reaches max push-through in which the shank head upper partial sphericalsurface 28 abuts the concave bottom surface 166 of the pressure insert150 and the retainer curvate inner surface 276 bears against the shanklower cylindrical outer surface 36.

With reference to FIGS. 112-113 , the uni-planar receiver sub-assembly346 is then pulled or moved back upward (or the universal shank headback downward) until the uni-planar retainer 270 snaps into and iscaptured by the horizontal capture recess 32, with the retainer curvateinner surface bearing 276 against the outwardly-facing inner recesssurface 34 of the shank head 22.

With reference to FIGS. 114-115 , the uni-planar receiver sub-assembly346 then continues back upward (or the universal shank head backdownward) while the uni-planar retainer 270 disengages from theuni-planar positioner 370 (which is vertically constrained by the upperand lower step surfaces 325, 329 of the positioner chamber 328) andbecomes seated on the partial spherical seating surface of the receiver322, with the opposed rounded pegs 279 being received back into theopposed pockets 333.

With reference to FIGS. 116-119 , the pressure insert 150 can now bedeployed with tooling that bears downwardly on the upper curvate seatingsurface 156 with considerable force to push the insert ridges 158downward out of the upper receiver grooves 320 and onto thediscontinuous cylindrical surface 318 of the central bore 314 of thereceiver 300. The tooling continues to push the insert 150 downwarduntil the insert ridges 158 snap into the lower receiver grooves 322 (asbest shown in FIG. 119 ), at which point the insert concave sphericalbottom surface 166 fully engages the shank head upper partial sphericalsurface 28 and the retainer outer partial spherical surface 274 alsofully engages the receiver partial spherical seating surface 332 toestablish a friction fit. The friction fit firmly holds the uni-planarreceiver 300 to the universal shank head 22 while allowing for movementof the receiver 300 relative to the bone anchor 20 with an appliedforce.

With reference to FIG. 118 , with the pressure insert 150 in thedeployed position, the leading edges 383 of the upper positionerprotrusions 382 can abut the cylindrical outer surface of the insertbase 162 to hold the positioner piece 172 in an expanded position withthe lower flanges 386 well-spaced from the now-pivotable retainer 270and universal shank head 22.

With further reference to FIGS. 119 and 124 , the bottom surfaces 165 ofthe pressure insert skirts 164 can also engage the upper edges of therounded pegs 279 of the uni-planar retainer 270, to secure and hold thepegs 279 down within their respective pockets 333 when transverse loadsor out-of-plane bending moments are applied to the uni-planar receiver300 by the shank acting on the uniplanar pivoting retainer.

With reference to FIGS. 120-121 , the friction fit engagement of theuni-planar receiver sub-assembly to the universal shank head 22 of thebone anchor 20 can provide the surgeon or medical professional with anumber of alignment options. For example, the friction fit allows forrotation of the uni-planar receiver 300 around the universal shank head22, with an applied axial twisting force, so as to align the receiverchannel 306 with the receiver channels of an adjacent pivotal boneanchor assembly. However, because the pegs 279 of the uni-planarretainer 270 are constrained from moving by the opposing pockets 333formed into lower seating surface 332, in the uni-planar embodiment therotational motion can be provided by the sliding of the inner surface276 of the uni-planar retainer 270 across the outwardly-facing innerrecess surface 34 of the horizontal capture recess 32.

The friction fit also allows for angulation of the uni-planar receiver300 relative the shank head 22, with an applied tangential moment force,also to align the receiver channel 306 with the receiver channels of anadjacent bone anchor assembly, through sliding frictional engagementbetween the retainer outer partial spherical surface 274 relative to thereceiver partial spherical seating surface 332. This angulation islimited to a single plane, however, due to the internal moment createdby the retainer pegs 279 abutting against both the sidewalls of thesurrounding pockets 333 and the underside surfaces 165 of the overlyingskirts 164 of the pressure insert 150, thereby preventing the uni-planarretainer 270 (and the attached shank head) from rotating in anydirection other than around the axis defined by the opposed retainerpegs 279.

The friction fit is provided from above by sliding frictional engagementbetween the insert concave spherical bottom surface 166 and the shankhead upper partial spherical surface 28 and/or the retainer outerpartial spherical surface 274, and from below by sliding frictionalengagement between the receiver partial spherical seating surface 332and the retainer outer partial spherical surface 274 and/or the shankhead lower partial spherical surface 38.

With reference to FIGS. 122-123 , the full assembly of an elongate rod90 and a closure 80 to uni-planar receiver sub-assembly may now becompleted. First, after a desired alignment and/or positioning of theuni-planar receiver sub-assembly 346 to the bone anchor 20 has beenachieved, the elongate rod 90 can then be installed (i.e. reduced) intothe receiver channel 306 until the underside surface of the rod engagesthe upper curvate rod seating surface 156 of the insert channel 154. Theclosure 80 can then be installed into the upper portion of the receivercentral bore 314, in which the continuous guide and advancementstructure 84 of the closure body 82 engages the discontinuous guide andadvancement structure 316 formed into the interior faces 310 of thereceiver upright arms 304.

The closure 80 can be threaded downwardly until the bottom surface 83 ofthe closure engages the top surface of the elongate rod 90. Furtherrotation/torqueing of the closure 80 can then be used to drive theelongate rod 90 downward into the pressure insert 150, which in turndrives the universal shank head 22 and uni-planar retainer 270 downwardinto the receiver partial spherical seating surface 332 to achieve afinal locking of the uni-planar bone anchor assembly 250, in which theuni-planar receiver sub-assembly 346 can no longer move relative to thebone anchor 20.

With reference to FIG. 124 , the closure break-off tab 88 can be shearedfrom the closure body 42 at a pre-determine torque value, therebyensuring that the pivotal bone anchor assembly is fully locked.

Illustrated in FIGS. 125-130 is another representative embodiment of amulti-planar pivotal bone anchor apparatus or assembly 410 in which theelongate rods and receivers have been replaced with multi-planarhousings 420 that provide for adjacent level connection. For example,the multi-planar housings 420 of the pivotal bone anchor assemblies 410can replace the multi-planar receivers discussed above with respect toFIGS. 1-69 , with the housings 420 containing a number of multi-planarcomponents, namely, a multi-planar retainer 436 and a multi-planartwo-piece positioner 440, that are substantially the same as thosemulti-planar components described above as residing in the multi-planarpivotal bone anchor assembly 10 shown in FIGS. 1-69 .

As shown in FIGS. 125-127 , in one aspect the housings 420 of thepivotal bone anchor assembly 410 can be separated into a male housing422 having a male chord projection 424 that is received in pivotalarrangement within a female receptacle 428 of a female housing 426immediately adjacent the male housing 422.

As shown in FIGS. 128-130 , the multi-planar housings 420 can furtherinclude a separate pressure insert 444 that has been modified to removethe upwardly projecting arm structures that define an insert channel,while still including external structure that can provide for thedownward deployment of the insert 444 to a non-floppy friction fitaround the universal shank head 22 prior to the installation of theclosure 448. With the housings 420 so equipped with these internals,each housing is also able to couple with the above-described universalshank heads 22 located at the_proximal ends of the bone anchors 20, asgenerally outlined above with respect to FIGS. 1-124 .

As shown in FIGS. 131-132 , in another embodiment the multi-planarhousings 420 of the multi-planar pivotal bone anchor apparatus orassembly 410 can include a multi-planar female housing 430 having afemale receptacle 432 that has been modified to include a set screw 434that is configured to lock a male chord projection (not shown) withinthe female receptacle 432. As can be seen in the drawings, the remainingcomponents of the multi-planar pivotal bone anchor assembly 410, namelythe multi-planar retainer 436, the multi-planar pined two-piecepositioner 440, the pressure insert 444, and the closure 448 can be thesame as those described above with reference to FIGS. 125-130 .

FIGS. 133-134 illustrate the same concept discussed above with respectto FIGS. 125-132 , except employ multi-planar housings 460 withdifferent exterior features and a one-piece positioner 480 that replacesthe two-piece positioner 440 described above with respect to themulti-planar pivotal bone anchor apparatus or assembly 410 of FIGS.125-132 . Besides the one-piece 480 and two-piece positioners 440respectively discussed with respect to FIGS. 133-134 and 125-132 , it isforeseen that other multi-piece positioners may be employed, such as forexample, three-piece, four-piece, and so forth, or even no positioner,wherein the multi-planar retainer is self-positioning, or aspects of thepressure insert 484 or of the receiver or housing 460 act against themulti-planar retainer 476 to position it within the receiver or housing460. The housings 460 of FIGS. 133-134 can also include the separatepressure insert 484 that has been modified from that shown in FIGS.1-124 to remove the upwardly projecting arm structures that defined aninsert channel, while still including external structure that canprovide for the downward deployment of the pressure insert 484 to anon-floppy friction fit around the universal shank head 22 located atthe proximal ends of the bone anchor 20, prior to the installation ofthe closure 488.

As can be understood by a comparison of the embodiments of themulti-planar receiver 100 and the uni-planar receiver 300 illustrated inFIGS. 1-124 and the embodiments of the adjacent level housings 420, 460illustrated in FIGS. 125-135 , both the receivers 100, 300 and thehousings 420, 460 have substantially the same retainer couplinginternals, namely, a pivoting retainer, a positioner (one- ortwo-piece), and a modified pressure insert residing therein, and whichcomponents are coupled to or deployed against the universal shank head22 of the bone anchor 20 in similar fashions and operations. Thereceivers 100, 300 and housings 420, 460 thus may be considereddifferent versions of a structural envelope that contains the internalretainer ring, positioner, and pressure insert.

As indicated above, the invention has been described herein in terms ofpreferred embodiments and methodologies considered by the inventor torepresent the best mode of carrying out the invention. It will beunderstood by the skilled artisan, however, that a wide range ofadditions, deletions, and modifications, both subtle and gross, may bemade to the illustrated and exemplary embodiments of the compositesubstrate without departing from the spirit and scope of the invention.These and other revisions might be made by those of skill in the artwithout departing from the spirit and scope of the invention that isconstrained only by the following claims.

What is claimed is:
 1. A pivotal bone anchor system for securing anelongate rod to a bone of a patient via closure tops, the pivotal boneanchor system comprising: a plurality of bone anchors, each bone anchorcomprising a longitudinal axis, a capture portion having a rounded shapewith a midsection defining a hemisphere plane perpendicular to thelongitudinal axis, and a unitary anchor portion opposite the captureportion configured for attachment to the bone, the capture portion beingwithout flat side faces and including at least one outer engagementsurface extending circumferentially around the capture portion at thehemisphere plane; at least one multi-planar receiver sub-assemblycomprising: a multi-planar receiver having a upper channel portionconfigured to receive the elongate rod and a lower base portion definingan internal cavity having a substantially continuous circumferentialpartial spherical seating surface proximate a bottom opening, and amulti-planar pivoting retainer having a circumferential partialspherical outer surface configured for multi-planar motion uponengagement with the seating surface of the internal cavity of themulti-planar receiver, and an inner surface configured to engage the atleast one outer engagement surface of one of the plurality of boneanchors to capture the bone anchor within the internal cavity of themulti-planar receiver; and at least one uni-planar receiver sub-assemblycomprising: a uni-planar receiver having a upper channel portionconfigured to receive the elongate rod and a lower base portion definingan internal cavity having a non-continuous circumferential partialspherical seating surface proximate a bottom opening with opposingpockets formed therein, and a uni-planar pivoting retainer having anon-continuous circumferential partial spherical outer surface withopposite pegs projecting outward therefrom, the partial spherical outsurface and pegs configured for uni-planar motion upon engagement withthe seating surface and opposing pockets of the internal cavity of theuni-planar receiver, respectively, and an inner surface configured toengage the at least one outer engagement surface of another of theplurality of bone anchors to capture the bone anchor within the internalcavity of the uni-planar receiver, wherein the capture portion of eachof the plurality of bone anchors is configured for capture by either ofthe at least one multi-planar receiver sub-assembly or the at least oneuni-planar receiver sub-assembly without further modification oradjustment.
 2. The pivotal bone anchor system of claim 1, wherein thecapture portion further comprises an upper partial spherical outersurface above the hemisphere plane, a lower partial spherical outersurface below the hemisphere plane.
 3. The pivotal bone anchor system ofclaim 2, wherein a radius of the upper partial spherical outer surfaceand a radius of lower partial spherical outer surface of the captureportion of the each of the plurality of bone anchors are substantiallyequal to the radii of the partial spherical outer surfaces of both themulti-planar and the uni-planar retainers.
 4. The pivotal bone anchorsystem of claim 1, wherein the at least one outer engagement surface ofthe capture portion of each bone anchor further comprise an inner recesssurface extending into and circumferentially around the capture portionat the hemisphere plane and an upper annular ledge surface that togetherdefine a horizontal capture recess.
 5. The pivotal bone anchor system ofclaim 4, wherein the inner surfaces of each multi-planar and uni-planarretainer is configured to snap into and engage the inner recess surfaceof the horizontal capture recess with a substantially neutral fit. 6.The pivotal bone anchor system of claim 4, wherein the inner recesssurface of each bone anchor is complementary with the inner surfaces ofthe multi-planar and the uni-planar retainers.
 7. The pivotal boneanchor system of claim 4, wherein the inner recess surface of each boneanchor further comprise a curved profile that curves downwardly andoutwardly as moving from the upper annular ledge surface to a lowerannular ledge surface.
 8. The pivotal bone anchor system of claim 4,wherein the inner recess surface of each bone anchor further comprises acylindrical profile that is substantially parallel with the longitudinalaxis of the bone anchor.
 9. The pivotal bone anchor system of claim 3,wherein the inner recess surface of each bone anchor further comprises aconical profile that is angled with respect to the longitudinal axis ofthe bone anchor.
 10. The pivotal bone anchor system of claim 1, whereinthe capture portions of each bone anchor are configured to be uploadedthrough the bottom openings and into the internal cavities of themulti-planar and uni-planar receivers, respectively, prior to capture bythe multi-planar and uni-planar retainers.
 11. The pivotal bone anchorsystem of claim 1, wherein each of the at least one multi-planarreceiver sub-assembly and the at least one uni-planar receiversub-assembly further comprises a positioner located in the internalcavity of the multi-planar or uni-planar receiver and configured tostabilize and centralize the multi-planar or uni-planar retainer abovethe bottom opening of the receiver.
 12. The pivotal bone anchor systemof claim 11, wherein the positioner located in the internal cavity ofthe multi-planar or uni-planar receiver further comprises two positionerpieces having center portions pinned to interior vertical sidewalls ofthe receiver cavity.
 13. The pivotal bone anchor system of claim 1,wherein each of the at least one multi-planar receiver sub-assembly andthe at least one uni-planar receiver sub-assembly further comprises apressure insert located in an upper first position in the upper channelportion of the multi-planar or uni-planar receiver with the pressureinsert having outwardly extending protrusions engagable with opposingupper grooves formed into the upper channel portion so as to prevent thepressure insert from moving back up within the upper channel portion.14. The pivotal bone anchor system of claim 13, wherein after a boneanchor capture portion is captured by the at least one multi-planarreceiver sub-assembly or the at least one uni-planar receiversub-assembly, respectively, the pressure insert is downwardly deployablein the upper channel portion from the upper first position to a lowersecond position by a tool, in which the insert outwardly extendingprotrusions are pushed downwardly from the opposing upper grooves andinto engagement with opposing lower grooves also formed into the upperchannel portion.
 15. The pivotal bone anchor system of claim 14, whereinthe pressure insert being located in the lower second position in theupper channel portion of the multi-planar or uni-planar receiver furthercomprises a friction fit position in which a bottom surface of thepressure insert becomes engaged with the upper partial spherical outersurface of the bone anchor capture portion with a non-floppy frictionfit.
 16. The pivotal bone anchor system of claim 1 and furthercomprising the elongate rod and a plurality of closure tops, whereineach of the plurality of closure tops is configured for positioningentirely within the upper channel portion of one the multi-planar oruni-planar receivers above the elongate rod and in engagement with amating structure formed into the upper channel portion to apply adownward pressure to a top of the elongate rod, so as to secure theelongate rod to the bone of the patient.